diff --git a/src/game/skills/druid-elemental.ts b/src/game/skills/druid-elemental.ts
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+/**
+ * Diablo II: Lord of Destruction v1.13c — Druid Elemental Skills Module
+ *
+ * Dedicated pure calculation, duration, synergy, absorption, and kinematics formulas
+ * for the 10 Druid Elemental Tree Skills:
+ * - Skill 225: Firestorm (ReqLevel 1)
+ * - Skill 229: Molten Boulder (ReqLevel 6)
+ * - Skill 230: Arctic Blast (ReqLevel 6)
+ * - Skill 234: Eruption / Fissure (ReqLevel 12)
+ * - Skill 235: Cyclone Armor (ReqLevel 12)
+ * - Skill 240: Twister (ReqLevel 18)
+ * - Skill 244: Volcano (ReqLevel 24)
+ * - Skill 245: Tornado (ReqLevel 24)
+ * - Skill 249: Armageddon (ReqLevel 30)
+ * - Skill 250: Hurricane (ReqLevel 30)
+ *
+ * 1.13c Ground Truth:
+ * - Skills.txt, Missiles.txt, Overlay.txt, States.txt (Patch_D2.mpq)
+ * - 5-band progression for elemental and physical damages
+ * - Strict fixed-point 24.8 mana calculations
+ * - Cyclone Armor absorption: Fire, Cold, Lightning ONLY (zero effect on Phys/Mag/Psn)
+ * - Arctic Blast continuous channeled cold stream with scaling chill length
+ * - Molten Boulder knockback and dual-type rolling & explosion damage
+ * - Twister 10-frame stun and 3-way chaotic spread
+ * - Tornado erratic wandering trajectory and 25-frame NextDelay
+ * - Armageddon & Hurricane duration scaling from synergies (+2s / blvl)
+ * - Zero runtime MPQ reading
+ */
+
+import { compute5BandScaling, compute3BandDuration } from '../engine/calc-ast.ts'
+
+// --- Skill IDs ---
+
+export const DRUID_ELEMENTAL_SKILL_IDS = {
+  FIRESTORM: 225,
+  MOLTEN_BOULDER: 229,
+  ARCTIC_BLAST: 230,
+  FISSURE: 234,
+  CYCLONE_ARMOR: 235,
+  TWISTER: 240,
+  VOLCANO: 244,
+  TORNADO: 245,
+  ARMAGEDDON: 249,
+  HURRICANE: 250,
+} as const
+
+// --- Interfaces for Skill Calculations ---
+
+export interface FirestormStats {
+  readonly minFireDamage: number
+  readonly maxFireDamage: number
+  readonly snakesCount: number
+  readonly synergyBonusPct: number
+  readonly cooldownFrames: number
+  readonly cooldownSeconds: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly castOverlay: string
+}
+
+export interface MoltenBoulderStats {
+  readonly minPhysicalDamage: number
+  readonly maxPhysicalDamage: number
+  readonly minFireDamage: number
+  readonly maxFireDamage: number
+  readonly knockbackRadius: number
+  readonly physSynergyBonusPct: number
+  readonly fireSynergyBonusPct: number
+  readonly cooldownFrames: number
+  readonly cooldownSeconds: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly missileName: string
+  readonly castOverlay: string
+}
+
+export interface ArcticBlastStats {
+  readonly minColdDamagePerSecond: number
+  readonly maxColdDamagePerSecond: number
+  readonly minColdDamagePerTick256: number
+  readonly maxColdDamagePerTick256: number
+  readonly chillDurationFrames: number
+  readonly chillDurationSeconds: number
+  readonly rangeYards: number
+  readonly synergyBonusPct: number
+  readonly manaCostPerTick256: number
+  readonly isChanneled: boolean
+  readonly missileName: string
+}
+
+export interface FissureStats {
+  readonly minFireDamage: number
+  readonly maxFireDamage: number
+  readonly durationFrames: number
+  readonly durationSeconds: number
+  readonly fissureVentsCount: number
+  readonly synergyBonusPct: number
+  readonly cooldownFrames: number
+  readonly cooldownSeconds: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly castOverlay: string
+}
+
+export interface CycloneArmorStats {
+  readonly baseAbsorption: number
+  readonly totalAbsorption: number
+  readonly totalAbsorption256: number
+  readonly synergyBonusPct: number
+  readonly absorbedElements: readonly ['fire', 'cold', 'lightning']
+  readonly unabsorbedElements: readonly ['physical', 'magic', 'poison']
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly overlayFront: string
+  readonly overlayBack: string
+  readonly stateName: string
+}
+
+export interface TwisterStats {
+  readonly minPhysicalDamage: number
+  readonly maxPhysicalDamage: number
+  readonly twisterCount: number
+  readonly stunDurationFrames: number
+  readonly stunDurationSeconds: number
+  readonly synergyBonusPct: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly missileName: string
+}
+
+export interface VolcanoStats {
+  readonly minPhysicalDamage: number
+  readonly maxPhysicalDamage: number
+  readonly minFireDamage: number
+  readonly maxFireDamage: number
+  readonly durationFrames: number
+  readonly durationSeconds: number
+  readonly radiusYards: number
+  readonly physSynergyBonusPct: number
+  readonly fireSynergyBonusPct: number
+  readonly cooldownFrames: number
+  readonly cooldownSeconds: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly castOverlay: string
+  readonly baseMissile: string
+  readonly subMissile: string
+}
+
+export interface TornadoStats {
+  readonly minPhysicalDamage: number
+  readonly maxPhysicalDamage: number
+  readonly nextDelayFrames: number
+  readonly synergyBonusPct: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly missileName: string
+}
+
+export interface ArmageddonStats {
+  readonly minPhysicalDamage: number
+  readonly maxPhysicalDamage: number
+  readonly minFireDamage: number
+  readonly maxFireDamage: number
+  readonly durationFrames: number
+  readonly durationSeconds: number
+  readonly radiusYards: number
+  readonly meteorIntervalFrames: number
+  readonly fireSynergyBonusPct: number
+  readonly cooldownFrames: number
+  readonly cooldownSeconds: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly castOverlay: string
+  readonly stateName: string
+}
+
+export interface HurricaneStats {
+  readonly minColdDamage: number
+  readonly maxColdDamage: number
+  readonly chillDurationFrames: number
+  readonly chillDurationSeconds: number
+  readonly durationFrames: number
+  readonly durationSeconds: number
+  readonly radiusYards: number
+  readonly pulseIntervalFrames: number
+  readonly coldSynergyBonusPct: number
+  readonly cooldownFrames: number
+  readonly cooldownSeconds: number
+  readonly manaCost: number
+  readonly manaCost256: number
+  readonly stateName: string
+}
+
+// --- Pure Calculation Functions ---
+
+/**
+ * Skill 225: Firestorm
+ * Ground Truth:
+ * - Fire damage: eMin=3 [3, 5, 7, 14, 21], eMax=6 [3, 6, 8, 15, 23]
+ * - Synergies: +23% fire damage per blvl in Molten Boulder & Eruption (Fissure)
+ * - Mana: 4 (constant), cooldown: 15 frames (0.6s)
+ * - 3 wandering fire trails (snakes)
+ */
+export function calculateFirestormStats(
+  slvl: number,
+  moltenBoulderBlvl = 0,
+  eruptionBlvl = 0,
+): FirestormStats {
+  const lvl = Math.max(1, slvl)
+  const mbPts = Math.max(0, moltenBoulderBlvl)
+  const erupPts = Math.max(0, eruptionBlvl)
+
+  const rawMin = compute5BandScaling(lvl, 3, 3, 5, 7, 14, 21)
+  const rawMax = compute5BandScaling(lvl, 6, 3, 6, 8, 15, 23)
+  const synergyBonusPct = (mbPts + erupPts) * 23
+
+  const minFireDamage = Math.trunc((rawMin * (100 + synergyBonusPct)) / 100)
+  const maxFireDamage = Math.trunc((rawMax * (100 + synergyBonusPct)) / 100)
+
+  return {
+    minFireDamage,
+    maxFireDamage,
+    snakesCount: 3,
+    synergyBonusPct,
+    cooldownFrames: 15,
+    cooldownSeconds: 15 / 25,
+    manaCost: 4,
+    manaCost256: 1024,
+    castOverlay: 'druid_fire_cast_1',
+  }
+}
+
+/**
+ * Skill 229: Molten Boulder
+ * Ground Truth:
+ * - Phys damage: minDam=6 [4, 7, 10, 13, 16], maxDam=12 [5, 8, 11, 14, 17]
+ * - Fire damage: eMin=6 [4, 7, 10, 13, 16], eMax=12 [5, 8, 11, 14, 17]
+ * - Synergies:
+ *   - Volcano: +10% physical damage / blvl
+ *   - Firestorm: +8% fire damage / blvl
+ * - Mana: mana=20, lvlmana=1, manashift=7 -> (20 + (lvl - 1)) << 7
+ * - Cooldown: 50 frames (2.0s)
+ */
+export function calculateMoltenBoulderStats(
+  slvl: number,
+  firestormBlvl = 0,
+  volcanoBlvl = 0,
+): MoltenBoulderStats {
+  const lvl = Math.max(1, slvl)
+  const fsPts = Math.max(0, firestormBlvl)
+  const volcPts = Math.max(0, volcanoBlvl)
+
+  const rawPhysMin = compute5BandScaling(lvl, 6, 4, 7, 10, 13, 16)
+  const rawPhysMax = compute5BandScaling(lvl, 12, 5, 8, 11, 14, 17)
+  const rawFireMin = rawPhysMin
+  const rawFireMax = rawPhysMax
+
+  const physSynergyBonusPct = volcPts * 10
+  const fireSynergyBonusPct = fsPts * 8
+
+  const minPhysicalDamage = Math.trunc((rawPhysMin * (100 + physSynergyBonusPct)) / 100)
+  const maxPhysicalDamage = Math.trunc((rawPhysMax * (100 + physSynergyBonusPct)) / 100)
+  const minFireDamage = Math.trunc((rawFireMin * (100 + fireSynergyBonusPct)) / 100)
+  const maxFireDamage = Math.trunc((rawFireMax * (100 + fireSynergyBonusPct)) / 100)
+
+  const manaCost256 = (20 + (lvl - 1)) << 7
+  const manaCost = manaCost256 >> 8
+
+  return {
+    minPhysicalDamage,
+    maxPhysicalDamage,
+    minFireDamage,
+    maxFireDamage,
+    knockbackRadius: 7,
+    physSynergyBonusPct,
+    fireSynergyBonusPct,
+    cooldownFrames: 50,
+    cooldownSeconds: 50 / 25,
+    manaCost,
+    manaCost256,
+    missileName: 'moltenboulderemerge',
+    castOverlay: 'druid_fire_cast_1',
+  }
+}
+
+/**
+ * Skill 230: Arctic Blast
+ * Ground Truth:
+ * - Channeled cold beam (like Inferno)
+ * - Cold damage per second: eMin=21 [16, 18, 20, 24, 29], eMax=40 [16, 19, 21, 25, 31]
+ * - Chill length: eLen=100 + (lvl-1)*15 frames
+ * - Range in yards: (35 + (lvl - 1) * 2) / 4 - 2
+ * - Synergies: +15% cold damage per blvl in Cyclone Armor & Hurricane
+ * - Mana per tick: (24 + (lvl - 1)) << 2 in 256ths (minMana=0)
+ */
+export function calculateArcticBlastStats(
+  slvl: number,
+  cycloneArmorBlvl = 0,
+  hurricaneBlvl = 0,
+): ArcticBlastStats {
+  const lvl = Math.max(1, slvl)
+  const caPts = Math.max(0, cycloneArmorBlvl)
+  const hurrPts = Math.max(0, hurricaneBlvl)
+
+  const rawMin = compute5BandScaling(lvl, 21, 16, 18, 20, 24, 29)
+  const rawMax = compute5BandScaling(lvl, 40, 16, 19, 21, 25, 31)
+  const synergyBonusPct = (caPts + hurrPts) * 15
+
+  const minColdDamagePerSecond = Math.trunc((rawMin * (100 + synergyBonusPct)) / 100)
+  const maxColdDamagePerSecond = Math.trunc((rawMax * (100 + synergyBonusPct)) / 100)
+
+  // In D2 1.13c, channeled spells apply damage per 25-frame tick in 256 fixed point:
+  const minColdDamagePerTick256 = Math.trunc((minColdDamagePerSecond * 256) / 25)
+  const maxColdDamagePerTick256 = Math.trunc((maxColdDamagePerSecond * 256) / 25)
+
+  const chillDurationFrames = 100 + (lvl - 1) * 15
+  const rangeYards = Number((((35 + (lvl - 1) * 2) / 4) - 2).toFixed(2))
+
+  const manaCostPerTick256 = (24 + (lvl - 1)) << 2
+
+  return {
+    minColdDamagePerSecond,
+    maxColdDamagePerSecond,
+    minColdDamagePerTick256,
+    maxColdDamagePerTick256,
+    chillDurationFrames,
+    chillDurationSeconds: chillDurationFrames / 25,
+    rangeYards,
+    synergyBonusPct,
+    manaCostPerTick256,
+    isChanneled: true,
+    missileName: 'arcticblast1',
+  }
+}
+
+/**
+ * Skill 234: Eruption / Fissure
+ * Ground Truth:
+ * - Fire damage: eMin=15 [6, 12, 16, 18, 22], eMax=25 [6, 12, 16, 19, 23]
+ * - Synergies: +12% fire damage per blvl in Firestorm & Volcano
+ * - Duration: 80 frames (3.2 seconds)
+ * - Mana: 15 (constant), Cooldown: 50 frames (2.0s)
+ */
+export function calculateFissureStats(
+  slvl: number,
+  firestormBlvl = 0,
+  volcanoBlvl = 0,
+): FissureStats {
+  const lvl = Math.max(1, slvl)
+  const fsPts = Math.max(0, firestormBlvl)
+  const volcPts = Math.max(0, volcanoBlvl)
+
+  const rawMin = compute5BandScaling(lvl, 15, 6, 12, 16, 18, 22)
+  const rawMax = compute5BandScaling(lvl, 25, 6, 12, 16, 19, 23)
+  const synergyBonusPct = (fsPts + volcPts) * 12
+
+  const minFireDamage = Math.trunc((rawMin * (100 + synergyBonusPct)) / 100)
+  const maxFireDamage = Math.trunc((rawMax * (100 + synergyBonusPct)) / 100)
+
+  return {
+    minFireDamage,
+    maxFireDamage,
+    durationFrames: 80,
+    durationSeconds: 80 / 25,
+    fissureVentsCount: 7,
+    synergyBonusPct,
+    cooldownFrames: 50,
+    cooldownSeconds: 50 / 25,
+    manaCost: 15,
+    manaCost256: 3840,
+    castOverlay: 'druid_fire_cast_2',
+  }
+}
+
+/**
+ * Skill 235: Cyclone Armor
+ * Ground Truth:
+ * - Base absorption: 40 + (slvl - 1) * 12
+ * - Synergies: +7% absorption per blvl in Twister, Tornado, Hurricane
+ * - Formula: (base * (100 + synPct)) / 100
+ * - Absorbs: Fire, Cold, Lightning ONLY.
+ * - Zero effect on: Physical, Magic, Poison.
+ * - Mana: 5 + (slvl - 1) * 1
+ */
+export function calculateCycloneArmorStats(
+  slvl: number,
+  twisterBlvl = 0,
+  tornadoBlvl = 0,
+  hurricaneBlvl = 0,
+): CycloneArmorStats {
+  const lvl = Math.max(1, slvl)
+  const twPts = Math.max(0, twisterBlvl)
+  const torPts = Math.max(0, tornadoBlvl)
+  const hurrPts = Math.max(0, hurricaneBlvl)
+
+  const baseAbsorption = 40 + (lvl - 1) * 12
+  const synergyBonusPct = (twPts + torPts + hurrPts) * 7
+  const totalAbsorption = Math.trunc((baseAbsorption * (100 + synergyBonusPct)) / 100)
+  const totalAbsorption256 = totalAbsorption << 8
+
+  const manaCost = 5 + (lvl - 1)
+  const manaCost256 = manaCost << 8
+
+  return {
+    baseAbsorption,
+    totalAbsorption,
+    totalAbsorption256,
+    synergyBonusPct,
+    absorbedElements: ['fire', 'cold', 'lightning'] as const,
+    unabsorbedElements: ['physical', 'magic', 'poison'] as const,
+    manaCost,
+    manaCost256,
+    overlayFront: 'cyclonearmor1front',
+    overlayBack: 'cyclonearmor1back',
+    stateName: 'cyclonearmor',
+  }
+}
+
+/**
+ * Skill 240: Twister
+ * Ground Truth:
+ * - Phys damage: minDam=12 [4, 7, 10, 13, 16], maxDam=16 [4, 7, 11, 14, 17]
+ * - Stun: 10 frames (0.4s)
+ * - Synergies: +10% damage per blvl in Tornado & Hurricane
+ * - Twisters count: 3
+ * - Mana: 7 (constant), Cooldown: 0
+ */
+export function calculateTwisterStats(
+  slvl: number,
+  tornadoBlvl = 0,
+  hurricaneBlvl = 0,
+): TwisterStats {
+  const lvl = Math.max(1, slvl)
+  const torPts = Math.max(0, tornadoBlvl)
+  const hurrPts = Math.max(0, hurricaneBlvl)
+
+  const rawMin = compute5BandScaling(lvl, 12, 4, 7, 10, 13, 16)
+  const rawMax = compute5BandScaling(lvl, 16, 4, 7, 11, 14, 17)
+  const synergyBonusPct = (torPts + hurrPts) * 10
+
+  const minPhysicalDamage = Math.trunc((rawMin * (100 + synergyBonusPct)) / 100)
+  const maxPhysicalDamage = Math.trunc((rawMax * (100 + synergyBonusPct)) / 100)
+
+  return {
+    minPhysicalDamage,
+    maxPhysicalDamage,
+    twisterCount: 3,
+    stunDurationFrames: 10,
+    stunDurationSeconds: 10 / 25,
+    synergyBonusPct,
+    manaCost: 7,
+    manaCost256: 1792,
+    missileName: 'twister',
+  }
+}
+
+/**
+ * Skill 244: Volcano
+ * Ground Truth:
+ * - Phys damage: minDam=8 [2, 4, 6, 8, 10], maxDam=10 [2, 4, 6, 8, 10]
+ * - Fire damage: eMin=8 [2, 4, 6, 8, 11], eMax=10 [2, 4, 6, 8, 13]
+ * - Synergies:
+ *   - Molten Boulder: +12% physical damage / blvl
+ *   - Eruption & Armageddon: +12% fire damage / blvl
+ * - Mana: 25 (constant), Cooldown: 100 frames (4.0s)
+ */
+export function calculateVolcanoStats(
+  slvl: number,
+  moltenBoulderBlvl = 0,
+  eruptionBlvl = 0,
+  armageddonBlvl = 0,
+): VolcanoStats {
+  const lvl = Math.max(1, slvl)
+  const mbPts = Math.max(0, moltenBoulderBlvl)
+  const erupPts = Math.max(0, eruptionBlvl)
+  const armPts = Math.max(0, armageddonBlvl)
+
+  const rawPhysMin = compute5BandScaling(lvl, 8, 2, 4, 6, 8, 10)
+  const rawPhysMax = compute5BandScaling(lvl, 10, 2, 4, 6, 8, 10)
+  const rawFireMin = compute5BandScaling(lvl, 8, 2, 4, 6, 8, 11)
+  const rawFireMax = compute5BandScaling(lvl, 10, 2, 4, 6, 8, 13)
+
+  const physSynergyBonusPct = mbPts * 12
+  const fireSynergyBonusPct = (erupPts + armPts) * 12
+
+  const minPhysicalDamage = Math.trunc((rawPhysMin * (100 + physSynergyBonusPct)) / 100)
+  const maxPhysicalDamage = Math.trunc((rawPhysMax * (100 + physSynergyBonusPct)) / 100)
+  const minFireDamage = Math.trunc((rawFireMin * (100 + fireSynergyBonusPct)) / 100)
+  const maxFireDamage = Math.trunc((rawFireMax * (100 + fireSynergyBonusPct)) / 100)
+
+  return {
+    minPhysicalDamage,
+    maxPhysicalDamage,
+    minFireDamage,
+    maxFireDamage,
+    durationFrames: 120, // 4.8s
+    durationSeconds: 120 / 25,
+    radiusYards: 12,
+    physSynergyBonusPct,
+    fireSynergyBonusPct,
+    cooldownFrames: 100,
+    cooldownSeconds: 100 / 25,
+    manaCost: 25,
+    manaCost256: 6400,
+    castOverlay: 'druid_fire_cast_2',
+    baseMissile: 'volcanobase',
+    subMissile: 'volcanorock',
+  }
+}
+
+/**
+ * Skill 245: Tornado
+ * Ground Truth:
+ * - Phys damage: minDam=25 [8, 14, 20, 24, 28], maxDam=35 [8, 15, 21, 25, 29]
+ * - Synergies: +9% damage per blvl in Cyclone Armor, Twister, Hurricane
+ * - NextDelay: 25 frames (1.0s)
+ * - Mana: 10 (constant), Cooldown: 0
+ */
+export function calculateTornadoStats(
+  slvl: number,
+  cycloneArmorBlvl = 0,
+  twisterBlvl = 0,
+  hurricaneBlvl = 0,
+): TornadoStats {
+  const lvl = Math.max(1, slvl)
+  const caPts = Math.max(0, cycloneArmorBlvl)
+  const twPts = Math.max(0, twisterBlvl)
+  const hurrPts = Math.max(0, hurricaneBlvl)
+
+  const rawMin = compute5BandScaling(lvl, 25, 8, 14, 20, 24, 28)
+  const rawMax = compute5BandScaling(lvl, 35, 8, 15, 21, 25, 29)
+  const synergyBonusPct = (caPts + twPts + hurrPts) * 9
+
+  const minPhysicalDamage = Math.trunc((rawMin * (100 + synergyBonusPct)) / 100)
+  const maxPhysicalDamage = Math.trunc((rawMax * (100 + synergyBonusPct)) / 100)
+
+  return {
+    minPhysicalDamage,
+    maxPhysicalDamage,
+    nextDelayFrames: 25,
+    synergyBonusPct,
+    manaCost: 10,
+    manaCost256: 2560,
+    missileName: 'tornado',
+  }
+}
+
+/**
+ * Skill 249: Armageddon
+ * Ground Truth:
+ * - Phys damage: minDam=4 [4, 6, 8, 10, 12], maxDam=16 [4, 7, 9, 12, 14]
+ * - Fire damage: eMin=25 [15, 20, 25, 31, 38], eMax=75 [16, 22, 27, 34, 40]
+ * - Duration: 250 frames (10s) + 50 frames (2s) per blvl in Eruption (Fissure)
+ * - Synergies: +14% fire damage per blvl in Firestorm, Molten Boulder, Volcano
+ * - Mana: 35 (constant), Cooldown: 150 frames (6.0s)
+ * - Radius: 8 yards (12 subtiles)
+ */
+export function calculateArmageddonStats(
+  slvl: number,
+  eruptionBlvl = 0,
+  firestormBlvl = 0,
+  moltenBoulderBlvl = 0,
+  volcanoBlvl = 0,
+): ArmageddonStats {
+  const lvl = Math.max(1, slvl)
+  const erupPts = Math.max(0, eruptionBlvl)
+  const fsPts = Math.max(0, firestormBlvl)
+  const mbPts = Math.max(0, moltenBoulderBlvl)
+  const volcPts = Math.max(0, volcanoBlvl)
+
+  const rawPhysMin = compute5BandScaling(lvl, 4, 4, 6, 8, 10, 12)
+  const rawPhysMax = compute5BandScaling(lvl, 16, 4, 7, 9, 12, 14)
+  const rawFireMin = compute5BandScaling(lvl, 25, 15, 20, 25, 31, 38)
+  const rawFireMax = compute5BandScaling(lvl, 75, 16, 22, 27, 34, 40)
+
+  const fireSynergyBonusPct = (fsPts + mbPts + volcPts) * 14
+
+  const minPhysicalDamage = rawPhysMin
+  const maxPhysicalDamage = rawPhysMax
+  const minFireDamage = Math.trunc((rawFireMin * (100 + fireSynergyBonusPct)) / 100)
+  const maxFireDamage = Math.trunc((rawFireMax * (100 + fireSynergyBonusPct)) / 100)
+
+  const durationFrames = 250 + erupPts * 50
+
+  return {
+    minPhysicalDamage,
+    maxPhysicalDamage,
+    minFireDamage,
+    maxFireDamage,
+    durationFrames,
+    durationSeconds: durationFrames / 25,
+    radiusYards: 8,
+    meteorIntervalFrames: 25, // 1 second between impacts
+    fireSynergyBonusPct,
+    cooldownFrames: 150,
+    cooldownSeconds: 150 / 25,
+    manaCost: 35,
+    manaCost256: 8960,
+    castOverlay: 'druid_fire_cast_2',
+    stateName: 'armageddon',
+  }
+}
+
+/**
+ * Skill 250: Hurricane
+ * Ground Truth:
+ * - Cold damage: eMin=25 [7, 10, 12, 14, 16], eMax=50 [7, 10, 12, 14, 16]
+ * - Chill length: 50 frames (2.0s)
+ * - Duration: 250 frames (10s) + 50 frames (2s) per blvl in Cyclone Armor
+ * - Synergies: +9% cold damage per blvl in Twister & Tornado
+ * - Mana: 30 (constant), Cooldown: 150 frames (6.0s)
+ * - Radius: 9 yards (13.5 subtiles)
+ * - Pulse interval: 20 frames (0.8s)
+ */
+export function calculateHurricaneStats(
+  slvl: number,
+  cycloneArmorBlvl = 0,
+  twisterBlvl = 0,
+  tornadoBlvl = 0,
+): HurricaneStats {
+  const lvl = Math.max(1, slvl)
+  const caPts = Math.max(0, cycloneArmorBlvl)
+  const twPts = Math.max(0, twisterBlvl)
+  const torPts = Math.max(0, tornadoBlvl)
+
+  const rawMin = compute5BandScaling(lvl, 25, 7, 10, 12, 14, 16)
+  const rawMax = compute5BandScaling(lvl, 50, 7, 10, 12, 14, 16)
+  const coldSynergyBonusPct = (twPts + torPts) * 9
+
+  const minColdDamage = Math.trunc((rawMin * (100 + coldSynergyBonusPct)) / 100)
+  const maxColdDamage = Math.trunc((rawMax * (100 + coldSynergyBonusPct)) / 100)
+
+  const durationFrames = 250 + caPts * 50
+
+  return {
+    minColdDamage,
+    maxColdDamage,
+    chillDurationFrames: 50,
+    chillDurationSeconds: 50 / 25,
+    durationFrames,
+    durationSeconds: durationFrames / 25,
+    radiusYards: 9,
+    pulseIntervalFrames: 20,
+    coldSynergyBonusPct,
+    cooldownFrames: 150,
+    cooldownSeconds: 150 / 25,
+    manaCost: 30,
+    manaCost256: 7680,
+    stateName: 'hurricane',
+  }
+}
+
+// --- Kinematics & Mechanics Simulation Helpers ---
+
+export interface AbsorptionResult {
+  readonly absorbed: number
+  readonly penetrated: number
+  readonly remainingArmor: number
+  readonly didDissipate: boolean
+}
+
+/**
+ * Simulate Cyclone Armor absorbing incoming elemental damage.
+ * Strictly absorbs Fire, Cold, and Lightning only.
+ * Physical, Magic, and Poison damage pass straight through with 0 absorption.
+ */
+export function simulateCycloneArmorAbsorption(
+  currentArmorCapacity: number,
+  incomingDamage: number,
+  damageType: 'fire' | 'cold' | 'lightning' | 'physical' | 'magic' | 'poison',
+): AbsorptionResult {
+  const isElemental = damageType === 'fire' || damageType === 'cold' || damageType === 'lightning'
+
+  if (!isElemental || currentArmorCapacity <= 0) {
+    return {
+      absorbed: 0,
+      penetrated: incomingDamage,
+      remainingArmor: Math.max(0, currentArmorCapacity),
+      didDissipate: currentArmorCapacity <= 0,
+    }
+  }
+
+  const absorbed = Math.min(currentArmorCapacity, incomingDamage)
+  const penetrated = incomingDamage - absorbed
+  const remainingArmor = currentArmorCapacity - absorbed
+
+  return {
+    absorbed,
+    penetrated,
+    remainingArmor,
+    didDissipate: remainingArmor <= 0,
+  }
+}
+
+export interface SerpentinePathPoint {
+  readonly x: number
+  readonly y: number
+}
+
+/**
+ * Calculate Firestorm meandering sinusoidal snake coordinates.
+ */
+export function calculateFirestormPathPoint(
+  originX: number,
+  originY: number,
+  targetX: number,
+  targetY: number,
+  snakeIndex: number, // 0, 1, 2
+  step: number,       // 0..40
+): SerpentinePathPoint {
+  const dx = targetX - originX
+  const dy = targetY - originY
+  const baseAngle = Math.atan2(dy, dx)
+  // Spread: -0.25, 0, +0.25 rad
+  const snakeAngle = baseAngle + (snakeIndex - 1) * 0.25
+  const speed = 8 // missile vel
+  const dist = step * speed
+
+  // Perpendicular sinusoidal wobble
+  const wobbleAmplitude = 14
+  const wobblePhase = step * 0.4 + snakeIndex * 2.1
+  const perpX = -Math.sin(snakeAngle) * Math.sin(wobblePhase) * wobbleAmplitude
+  const perpY = Math.cos(snakeAngle) * Math.sin(wobblePhase) * wobbleAmplitude
+
+  return {
+    x: originX + Math.cos(snakeAngle) * dist + perpX,
+    y: originY + Math.sin(snakeAngle) * dist + perpY,
+  }
+}
+
+export interface TornadoWanderPoint {
+  readonly x: number
+  readonly y: number
+  readonly currentPhase: number
+}
+
+/**
+ * Simulate Tornado wandering path progression.
+ */
+export function simulateTornadoWanderStep(
+  currentX: number,
+  currentY: number,
+  baseHeadingRad: number,
+  currentPhase: number,
+  stepSpeed = 8,
+): TornadoWanderPoint {
+  // Angular wobble
+  const nextPhase = currentPhase + 0.35
+  const wobbleAngle = baseHeadingRad + Math.sin(nextPhase) * 0.8
+  return {
+    x: currentX + Math.cos(wobbleAngle) * stepSpeed,
+    y: currentY + Math.sin(wobbleAngle) * stepSpeed,
+    currentPhase: nextPhase,
+  }
+}
+
+export interface ArmageddonImpactLocation {
+  readonly x: number
+  readonly y: number
+  readonly distanceYards: number
+}
+
+/**
+ * Determine random impact location for an Armageddon meteor drop around Druid.
+ */
+export function calculateArmageddonImpactLocation(
+  druidX: number,
+  druidY: number,
+  randomAngleRad: number,
+  randomRadiusRatio: number, // 0..1
+  maxRadiusYards = 8,
+): ArmageddonImpactLocation {
+  const radiusYards = Math.sqrt(Math.max(0, Math.min(1, randomRadiusRatio))) * maxRadiusYards
+  const radiusPx = radiusYards * 16 // 16px per yard in 2:1 isometric ground
+  return {
+    x: druidX + Math.cos(randomAngleRad) * radiusPx,
+    y: druidY + Math.sin(randomAngleRad) * radiusPx * 0.5, // 2:1 perspective
+    distanceYards: Number(radiusYards.toFixed(2)),
+  }
+}
diff --git a/tests/skills/dru/adv-dru-elemental-stress.test.ts b/tests/skills/dru/adv-dru-elemental-stress.test.ts
new file mode 100644
index 0000000..a3c0239
--- /dev/null
+++ b/tests/skills/dru/adv-dru-elemental-stress.test.ts
@@ -0,0 +1,599 @@
+import { describe, expect, it } from 'vitest'
+import {
+  calculateFirestormStats,
+  calculateMoltenBoulderStats,
+  calculateArcticBlastStats,
+  calculateFissureStats,
+  calculateCycloneArmorStats,
+  calculateTwisterStats,
+  calculateVolcanoStats,
+  calculateTornadoStats,
+  calculateArmageddonStats,
+  calculateHurricaneStats,
+  simulateCycloneArmorAbsorption,
+  calculateFirestormPathPoint,
+  simulateTornadoWanderStep,
+  calculateArmageddonImpactLocation,
+} from '../../../src/game/skills/druid-elemental.ts'
+import { BATCH1_SKILLS } from '../../../src/game/skills.ts'
+import { getSharedDataRegistry } from '../../../src/game/engine/data-registry.ts'
+import { UnitStatList } from '../../../src/game/engine/stat-list.ts'
+import { evaluateSkill113c, getRegisteredSkillModule } from '../../../src/game/skills/registry.ts'
+
+describe('Milestone M22 — Druid Elemental Skills Parity & Adversarial Stress Suite', () => {
+  // =========================================================================
+  // Dimension 1: Exact 1.13c Numerical Scaling & Level Progressions
+  // =========================================================================
+  describe('Dimension 1: Exact 1.13c Numerical Scaling & Formulas', () => {
+    it('1.1 Firestorm (225): Evaluates exact fire damage, 3-snake count, and +23%/blvl synergy', () => {
+      // slvl 1
+      const fs1 = calculateFirestormStats(1, 0, 0)
+      expect(fs1.minFireDamage).toBe(3)
+      expect(fs1.maxFireDamage).toBe(6)
+      expect(fs1.snakesCount).toBe(3)
+      expect(fs1.manaCost).toBe(4)
+      expect(fs1.manaCost256).toBe(1024)
+      expect(fs1.cooldownFrames).toBe(15)
+      expect(fs1.cooldownSeconds).toBe(0.6)
+      expect(fs1.castOverlay).toBe('druid_fire_cast_1')
+
+      // slvl 10: 3 + 7*3 + 2*5 = 34 min, 6 + 7*3 + 2*6 = 39 max
+      const fs10 = calculateFirestormStats(10, 0, 0)
+      expect(fs10.minFireDamage).toBe(34)
+      expect(fs10.maxFireDamage).toBe(39)
+
+      // slvl 20: 3 + 7*3 + 8*5 + 4*7 = 92 min, 6 + 7*3 + 8*6 + 4*8 = 107 max
+      const fs20 = calculateFirestormStats(20, 0, 0)
+      expect(fs20.minFireDamage).toBe(92)
+      expect(fs20.maxFireDamage).toBe(107)
+
+      // Synergy: 10 in Molten Boulder + 10 in Fissure = +460% fire damage
+      const fs20Syn = calculateFirestormStats(20, 10, 10)
+      expect(fs20Syn.synergyBonusPct).toBe(460)
+      expect(fs20Syn.minFireDamage).toBe(Math.trunc((92 * 560) / 100)) // 515
+      expect(fs20Syn.maxFireDamage).toBe(Math.trunc((107 * 560) / 100)) // 599
+    })
+
+    it('1.2 Molten Boulder (229): Evaluates dual physical/fire damage and fixed-point mana scaling', () => {
+      // slvl 1
+      const mb1 = calculateMoltenBoulderStats(1, 0, 0)
+      expect(mb1.minPhysicalDamage).toBe(6)
+      expect(mb1.maxPhysicalDamage).toBe(12)
+      expect(mb1.minFireDamage).toBe(6)
+      expect(mb1.maxFireDamage).toBe(12)
+      expect(mb1.manaCost).toBe(10)
+      expect(mb1.manaCost256).toBe(2560)
+      expect(mb1.cooldownFrames).toBe(50)
+      expect(mb1.knockbackRadius).toBe(7)
+
+      // slvl 10: base: 6 + 7*4 + 2*7 = 48 min, 12 + 7*5 + 2*8 = 63 max
+      // mana: (20 + 9) << 7 = 3712 -> manaCost = 14
+      const mb10 = calculateMoltenBoulderStats(10, 0, 0)
+      expect(mb10.minPhysicalDamage).toBe(48)
+      expect(mb10.maxPhysicalDamage).toBe(63)
+      expect(mb10.minFireDamage).toBe(48)
+      expect(mb10.maxFireDamage).toBe(63)
+      expect(mb10.manaCost).toBe(14)
+      expect(mb10.manaCost256).toBe(3712)
+
+      // slvl 20: base: 48 + 6*7 + 4*10 = 130 min, 63 + 6*8 + 4*11 = 155 max
+      // mana: (20 + 19) << 7 = 4992 -> manaCost = 19
+      const mb20 = calculateMoltenBoulderStats(20, 0, 0)
+      expect(mb20.minPhysicalDamage).toBe(130)
+      expect(mb20.maxPhysicalDamage).toBe(155)
+      expect(mb20.manaCost).toBe(19)
+      expect(mb20.manaCost256).toBe(4992)
+
+      // Synergies: Volcano (+10%/lvl phys), Firestorm (+8%/lvl fire)
+      const mb20Syn = calculateMoltenBoulderStats(20, 20, 20)
+      expect(mb20Syn.physSynergyBonusPct).toBe(200)
+      expect(mb20Syn.fireSynergyBonusPct).toBe(160)
+      expect(mb20Syn.minPhysicalDamage).toBe(130 * 3) // 390
+      expect(mb20Syn.maxPhysicalDamage).toBe(155 * 3) // 465
+      expect(mb20Syn.minFireDamage).toBe(Math.trunc((130 * 260) / 100)) // 338
+      expect(mb20Syn.maxFireDamage).toBe(Math.trunc((155 * 260) / 100)) // 403
+    })
+
+    it('1.3 Arctic Blast (230): Evaluates continuous channeled cold damage, expanding arc, and chill scaling', () => {
+      // slvl 1
+      const ab1 = calculateArcticBlastStats(1, 0, 0)
+      expect(ab1.minColdDamagePerSecond).toBe(21)
+      expect(ab1.maxColdDamagePerSecond).toBe(40)
+      expect(ab1.chillDurationFrames).toBe(100) // 4s
+      expect(ab1.chillDurationSeconds).toBe(4.0)
+      expect(ab1.rangeYards).toBe(6.75) // (35/4) - 2 = 8.75 - 2 = 6.75
+      expect(ab1.manaCostPerTick256).toBe(96) // 24 << 2
+      expect(ab1.isChanneled).toBe(true)
+
+      // slvl 10: 21 + 7*16 + 2*18 = 169 min, 40 + 7*16 + 2*19 = 190 max
+      const ab10 = calculateArcticBlastStats(10, 0, 0)
+      expect(ab10.minColdDamagePerSecond).toBe(169)
+      expect(ab10.maxColdDamagePerSecond).toBe(190)
+      expect(ab10.chillDurationFrames).toBe(235) // 100 + 9*15 = 235 (9.4s)
+      expect(ab10.manaCostPerTick256).toBe(132) // (24 + 9) << 2 = 132
+
+      // slvl 20: 169 + 6*18 + 4*20 = 357 min, 190 + 6*19 + 4*21 = 388 max
+      const ab20 = calculateArcticBlastStats(20, 0, 0)
+      expect(ab20.minColdDamagePerSecond).toBe(357)
+      expect(ab20.maxColdDamagePerSecond).toBe(388)
+      expect(ab20.chillDurationFrames).toBe(385) // 100 + 19*15 = 385 (15.4s)
+      expect(ab20.manaCostPerTick256).toBe(172) // (24 + 19) << 2 = 172
+
+      // Synergy: Cyclone Armor + Hurricane (+15% / blvl each)
+      const ab20Syn = calculateArcticBlastStats(20, 20, 20)
+      expect(ab20Syn.synergyBonusPct).toBe(600)
+      expect(ab20Syn.minColdDamagePerSecond).toBe(357 * 7) // 2499
+      expect(ab20Syn.maxColdDamagePerSecond).toBe(388 * 7) // 2716
+    })
+
+    it('1.4 Eruption / Fissure (234): Evaluates geological fire damage and duration', () => {
+      // slvl 1
+      const f1 = calculateFissureStats(1, 0, 0)
+      expect(f1.minFireDamage).toBe(15)
+      expect(f1.maxFireDamage).toBe(25)
+      expect(f1.durationFrames).toBe(80) // 3.2s
+      expect(f1.cooldownFrames).toBe(50) // 2.0s
+      expect(f1.manaCost).toBe(15)
+      expect(f1.manaCost256).toBe(3840)
+
+      // slvl 10: 15 + 7*6 + 2*12 = 81 min, 25 + 7*6 + 2*12 = 91 max
+      const f10 = calculateFissureStats(10, 0, 0)
+      expect(f10.minFireDamage).toBe(81)
+      expect(f10.maxFireDamage).toBe(91)
+
+      // slvl 20: 81 + 6*12 + 4*16 = 217 min, 91 + 6*12 + 4*16 = 227 max
+      const f20 = calculateFissureStats(20, 0, 0)
+      expect(f20.minFireDamage).toBe(217)
+      expect(f20.maxFireDamage).toBe(227)
+
+      // Synergies: Firestorm + Volcano (+12%/lvl)
+      const f20Syn = calculateFissureStats(20, 20, 20)
+      expect(f20Syn.synergyBonusPct).toBe(480)
+      expect(f20Syn.minFireDamage).toBe(Math.trunc((217 * 580) / 100)) // 1258
+      expect(f20Syn.maxFireDamage).toBe(Math.trunc((227 * 580) / 100)) // 1316
+    })
+
+    it('1.5 Cyclone Armor (235): Evaluates base absorption, synergy scaling, and mana progression', () => {
+      // slvl 1
+      const ca1 = calculateCycloneArmorStats(1, 0, 0, 0)
+      expect(ca1.baseAbsorption).toBe(40)
+      expect(ca1.totalAbsorption).toBe(40)
+      expect(ca1.totalAbsorption256).toBe(40 << 8)
+      expect(ca1.manaCost).toBe(5)
+      expect(ca1.manaCost256).toBe(1280)
+      expect(ca1.absorbedElements).toEqual(['fire', 'cold', 'lightning'])
+      expect(ca1.unabsorbedElements).toEqual(['physical', 'magic', 'poison'])
+
+      // slvl 10: 40 + 9*12 = 148, mana: 5 + 9 = 14
+      const ca10 = calculateCycloneArmorStats(10, 0, 0, 0)
+      expect(ca10.baseAbsorption).toBe(148)
+      expect(ca10.totalAbsorption).toBe(148)
+      expect(ca10.manaCost).toBe(14)
+      expect(ca10.manaCost256).toBe(3584)
+
+      // slvl 20: 40 + 19*12 = 268, mana: 5 + 19 = 24
+      const ca20 = calculateCycloneArmorStats(20, 0, 0, 0)
+      expect(ca20.baseAbsorption).toBe(268)
+      expect(ca20.totalAbsorption).toBe(268)
+      expect(ca20.manaCost).toBe(24)
+      expect(ca20.manaCost256).toBe(6144)
+
+      // Synergies: Twister (20) + Tornado (20) + Hurricane (20) = 60 * 7% = +420%
+      const ca20Syn = calculateCycloneArmorStats(20, 20, 20, 20)
+      expect(ca20Syn.synergyBonusPct).toBe(420)
+      expect(ca20Syn.totalAbsorption).toBe(Math.trunc((268 * 520) / 100)) // 1393
+    })
+
+    it('1.6 Twister (240): Evaluates 3-way dispersion, physical damage, and 10-frame stun', () => {
+      // slvl 1
+      const tw1 = calculateTwisterStats(1, 0, 0)
+      expect(tw1.minPhysicalDamage).toBe(12)
+      expect(tw1.maxPhysicalDamage).toBe(16)
+      expect(tw1.twisterCount).toBe(3)
+      expect(tw1.stunDurationFrames).toBe(10)
+      expect(tw1.stunDurationSeconds).toBe(0.4)
+      expect(tw1.manaCost).toBe(7)
+      expect(tw1.manaCost256).toBe(1792)
+
+      // slvl 10: 12 + 7*4 + 2*7 = 54 min, 16 + 7*4 + 2*7 = 58 max
+      const tw10 = calculateTwisterStats(10, 0, 0)
+      expect(tw10.minPhysicalDamage).toBe(54)
+      expect(tw10.maxPhysicalDamage).toBe(58)
+
+      // slvl 20: 54 + 6*7 + 4*10 = 136 min, 58 + 6*7 + 4*11 = 144 max
+      const tw20 = calculateTwisterStats(20, 0, 0)
+      expect(tw20.minPhysicalDamage).toBe(136)
+      expect(tw20.maxPhysicalDamage).toBe(144)
+
+      // Synergies: Tornado + Hurricane (+10%/lvl each)
+      const tw20Syn = calculateTwisterStats(20, 20, 20)
+      expect(tw20Syn.synergyBonusPct).toBe(400)
+      expect(tw20Syn.minPhysicalDamage).toBe(136 * 5) // 680
+      expect(tw20Syn.maxPhysicalDamage).toBe(144 * 5) // 720
+    })
+
+    it('1.7 Volcano (244): Evaluates physical and fire damage split and cooldown', () => {
+      // slvl 1
+      const v1 = calculateVolcanoStats(1, 0, 0, 0)
+      expect(v1.minPhysicalDamage).toBe(8)
+      expect(v1.maxPhysicalDamage).toBe(10)
+      expect(v1.minFireDamage).toBe(8)
+      expect(v1.maxFireDamage).toBe(10)
+      expect(v1.cooldownFrames).toBe(100)
+      expect(v1.cooldownSeconds).toBe(4.0)
+      expect(v1.manaCost).toBe(25)
+      expect(v1.manaCost256).toBe(6400)
+
+      // slvl 10: phys: 8 + 7*2 + 2*4 = 30 min, 10 + 7*2 + 2*4 = 32 max
+      // fire: same at slvl 10
+      const v10 = calculateVolcanoStats(10, 0, 0, 0)
+      expect(v10.minPhysicalDamage).toBe(30)
+      expect(v10.maxPhysicalDamage).toBe(32)
+      expect(v10.minFireDamage).toBe(30)
+      expect(v10.maxFireDamage).toBe(32)
+
+      // slvl 20: phys: 30 + 6*4 + 4*6 = 78 min, 32 + 6*4 + 4*6 = 80 max
+      const v20 = calculateVolcanoStats(20, 0, 0, 0)
+      expect(v20.minPhysicalDamage).toBe(78)
+      expect(v20.maxPhysicalDamage).toBe(80)
+
+      // Synergies: Molten Boulder (+12% phys), Eruption & Armageddon (+12% fire)
+      const v20Syn = calculateVolcanoStats(20, 20, 20, 20)
+      expect(v20Syn.physSynergyBonusPct).toBe(240)
+      expect(v20Syn.fireSynergyBonusPct).toBe(480)
+      expect(v20Syn.minPhysicalDamage).toBe(Math.trunc((78 * 340) / 100)) // 265
+      expect(v20Syn.minFireDamage).toBe(Math.trunc((78 * 580) / 100)) // 452
+    })
+
+    it('1.8 Tornado (245): Evaluates heavy physical vortex damage and NextDelay', () => {
+      // slvl 1
+      const tor1 = calculateTornadoStats(1, 0, 0, 0)
+      expect(tor1.minPhysicalDamage).toBe(25)
+      expect(tor1.maxPhysicalDamage).toBe(35)
+      expect(tor1.nextDelayFrames).toBe(25)
+      expect(tor1.manaCost).toBe(10)
+      expect(tor1.manaCost256).toBe(2560)
+
+      // slvl 10: 25 + 7*8 + 2*14 = 109 min, 35 + 7*8 + 2*15 = 121 max
+      const tor10 = calculateTornadoStats(10, 0, 0, 0)
+      expect(tor10.minPhysicalDamage).toBe(109)
+      expect(tor10.maxPhysicalDamage).toBe(121)
+
+      // slvl 20: 109 + 6*14 + 4*20 = 273 min, 121 + 6*15 + 4*21 = 295 max
+      const tor20 = calculateTornadoStats(20, 0, 0, 0)
+      expect(tor20.minPhysicalDamage).toBe(273)
+      expect(tor20.maxPhysicalDamage).toBe(295)
+
+      // Synergies: Cyclone Armor + Twister + Hurricane (+9% each / blvl)
+      const tor20Syn = calculateTornadoStats(20, 20, 20, 20)
+      expect(tor20Syn.synergyBonusPct).toBe(540)
+      expect(tor20Syn.minPhysicalDamage).toBe(Math.trunc((273 * 640) / 100)) // 1747
+      expect(tor20Syn.maxPhysicalDamage).toBe(Math.trunc((295 * 640) / 100)) // 1888
+    })
+
+    it('1.9 Armageddon (249): Evaluates fire + physical meteor rain and duration scaling', () => {
+      // slvl 1
+      const arm1 = calculateArmageddonStats(1, 0, 0, 0, 0)
+      expect(arm1.minPhysicalDamage).toBe(4)
+      expect(arm1.maxPhysicalDamage).toBe(16)
+      expect(arm1.minFireDamage).toBe(25)
+      expect(arm1.maxFireDamage).toBe(75)
+      expect(arm1.durationFrames).toBe(250) // 10.0s
+      expect(arm1.radiusYards).toBe(8)
+      expect(arm1.cooldownFrames).toBe(150) // 6.0s
+      expect(arm1.manaCost).toBe(35)
+      expect(arm1.manaCost256).toBe(8960)
+
+      // Duration synergy: +50 frames (2.0s) per blvl in Eruption (Fissure)
+      const arm1WithFissure = calculateArmageddonStats(1, 15, 0, 0, 0)
+      expect(arm1WithFissure.durationFrames).toBe(250 + 15 * 50) // 1000 frames = 40s
+      expect(arm1WithFissure.durationSeconds).toBe(40.0)
+
+      // slvl 20 fire damage: 25 + 7*15 + 8*20 + 4*25 = 390 min, 75 + 7*16 + 8*22 + 4*27 = 471 max
+      const arm20 = calculateArmageddonStats(20, 0, 0, 0, 0)
+      expect(arm20.minFireDamage).toBe(390)
+      expect(arm20.maxFireDamage).toBe(471)
+
+      // Damage synergy: Firestorm, Molten Boulder, Volcano (+14% each / blvl)
+      const arm20Syn = calculateArmageddonStats(20, 0, 20, 20, 20)
+      expect(arm20Syn.fireSynergyBonusPct).toBe(840) // 60 * 14
+      expect(arm20Syn.minFireDamage).toBe(Math.trunc((390 * 940) / 100)) // 3666
+      expect(arm20Syn.maxFireDamage).toBe(Math.trunc((471 * 940) / 100)) // 4427
+    })
+
+    it('1.10 Hurricane (250): Evaluates orbiting blizzard cold damage, chill, and duration scaling', () => {
+      // slvl 1
+      const hurr1 = calculateHurricaneStats(1, 0, 0, 0)
+      expect(hurr1.minColdDamage).toBe(25)
+      expect(hurr1.maxColdDamage).toBe(50)
+      expect(hurr1.chillDurationFrames).toBe(50) // 2.0s
+      expect(hurr1.durationFrames).toBe(250) // 10.0s
+      expect(hurr1.radiusYards).toBe(9)
+      expect(hurr1.cooldownFrames).toBe(150) // 6.0s
+      expect(hurr1.manaCost).toBe(30)
+      expect(hurr1.manaCost256).toBe(7680)
+
+      // Duration synergy: +50 frames (2.0s) per blvl in Cyclone Armor
+      const hurr1WithArmor = calculateHurricaneStats(1, 20, 0, 0)
+      expect(hurr1WithArmor.durationFrames).toBe(250 + 20 * 50) // 1250 frames = 50s
+      expect(hurr1WithArmor.durationSeconds).toBe(50.0)
+
+      // slvl 20 cold damage: 25 + 7*7 + 8*10 + 4*12 = 202 min, 50 + 7*7 + 8*10 + 4*12 = 227 max
+      const hurr20 = calculateHurricaneStats(20, 0, 0, 0)
+      expect(hurr20.minColdDamage).toBe(202)
+      expect(hurr20.maxColdDamage).toBe(227)
+
+      // Damage synergy: Twister + Tornado (+9% each / blvl)
+      const hurr20Syn = calculateHurricaneStats(20, 0, 20, 20)
+      expect(hurr20Syn.coldSynergyBonusPct).toBe(360)
+      expect(hurr20Syn.minColdDamage).toBe(Math.trunc((202 * 460) / 100)) // 929
+      expect(hurr20Syn.maxColdDamage).toBe(Math.trunc((227 * 460) / 100)) // 1044
+    })
+  })
+
+  // =========================================================================
+  // Dimension 2: Cyclone Armor Strict Absorption Matrix & Edge Cases
+  // =========================================================================
+  describe('Dimension 2: Cyclone Armor Strict Absorption Matrix & Edge Cases', () => {
+    it('2.1 Strictly absorbs Fire, Cold, and Lightning elemental damage', () => {
+      const initialCapacity = 500
+
+      // Fire damage
+      const fireRes = simulateCycloneArmorAbsorption(initialCapacity, 150, 'fire')
+      expect(fireRes.absorbed).toBe(150)
+      expect(fireRes.penetrated).toBe(0)
+      expect(fireRes.remainingArmor).toBe(350)
+      expect(fireRes.didDissipate).toBe(false)
+
+      // Cold damage
+      const coldRes = simulateCycloneArmorAbsorption(fireRes.remainingArmor, 200, 'cold')
+      expect(coldRes.absorbed).toBe(200)
+      expect(coldRes.penetrated).toBe(0)
+      expect(coldRes.remainingArmor).toBe(150)
+      expect(coldRes.didDissipate).toBe(false)
+
+      // Lightning damage
+      const ltngRes = simulateCycloneArmorAbsorption(coldRes.remainingArmor, 100, 'lightning')
+      expect(ltngRes.absorbed).toBe(100)
+      expect(ltngRes.penetrated).toBe(0)
+      expect(ltngRes.remainingArmor).toBe(50)
+      expect(ltngRes.didDissipate).toBe(false)
+    })
+
+    it('2.2 Passes Physical, Magic, and Poison damage straight through with zero absorption', () => {
+      const initialCapacity = 500
+
+      // Physical damage (e.g. crushing blow, arrow)
+      const physRes = simulateCycloneArmorAbsorption(initialCapacity, 250, 'physical')
+      expect(physRes.absorbed).toBe(0)
+      expect(physRes.penetrated).toBe(250)
+      expect(physRes.remainingArmor).toBe(500)
+      expect(physRes.didDissipate).toBe(false)
+
+      // Magic damage (e.g. Bone Spear, Blessed Hammer)
+      const magRes = simulateCycloneArmorAbsorption(initialCapacity, 300, 'magic')
+      expect(magRes.absorbed).toBe(0)
+      expect(magRes.penetrated).toBe(300)
+      expect(magRes.remainingArmor).toBe(500)
+      expect(magRes.didDissipate).toBe(false)
+
+      // Poison damage (e.g. Poison Nova)
+      const psnRes = simulateCycloneArmorAbsorption(initialCapacity, 400, 'poison')
+      expect(psnRes.absorbed).toBe(0)
+      expect(psnRes.penetrated).toBe(400)
+      expect(psnRes.remainingArmor).toBe(500)
+      expect(psnRes.didDissipate).toBe(false)
+    })
+
+    it('2.3 Depletion & Dissipation: Absorbs up to remaining capacity and passes remaining damage to player', () => {
+      const initialCapacity = 100
+
+      // Huge incoming fire attack (400 fire damage against 100 capacity)
+      const overRes = simulateCycloneArmorAbsorption(initialCapacity, 400, 'fire')
+      expect(overRes.absorbed).toBe(100)
+      expect(overRes.penetrated).toBe(300)
+      expect(overRes.remainingArmor).toBe(0)
+      expect(overRes.didDissipate).toBe(true)
+
+      // Subsequent attacks hit directly with 0 armor
+      const postRes = simulateCycloneArmorAbsorption(overRes.remainingArmor, 50, 'lightning')
+      expect(postRes.absorbed).toBe(0)
+      expect(postRes.penetrated).toBe(50)
+      expect(postRes.remainingArmor).toBe(0)
+      expect(postRes.didDissipate).toBe(true)
+    })
+  })
+
+  // =========================================================================
+  // Dimension 3: Kinematics, Trajectory & Multi-Missile Mechanics
+  // =========================================================================
+  describe('Dimension 3: Kinematics, Trajectory & Multi-Missile Mechanics', () => {
+    it('3.1 Firestorm: 3 snakes disperse along divergent angular paths with non-collinear coordinates', () => {
+      const originX = 100
+      const originY = 100
+      const targetX = 300
+      const targetY = 100
+
+      // Step 10
+      const s0 = calculateFirestormPathPoint(originX, originY, targetX, targetY, 0, 10)
+      const s1 = calculateFirestormPathPoint(originX, originY, targetX, targetY, 1, 10)
+      const s2 = calculateFirestormPathPoint(originX, originY, targetX, targetY, 2, 10)
+
+      // All 3 snakes must travel forward (x > originX)
+      expect(s0.x).toBeGreaterThan(originX)
+      expect(s1.x).toBeGreaterThan(originX)
+      expect(s2.x).toBeGreaterThan(originX)
+
+      // The 3 snakes must be spatially separated along the Y axis
+      expect(s0.y).not.toBe(s1.y)
+      expect(s1.y).not.toBe(s2.y)
+      expect(s0.y).not.toBe(s2.y)
+    })
+
+    it('3.2 Tornado: Wanders smoothly with continuous lateral oscillation without snapping backwards', () => {
+      let x = 200
+      let y = 200
+      const baseHeading = 0 // moving East
+      let phase = 0
+
+      const history: { x: number; y: number }[] = []
+      for (let step = 0; step < 20; step++) {
+        const next = simulateTornadoWanderStep(x, y, baseHeading, phase, 8)
+        expect(next.x).toBeGreaterThan(x) // Monotonically progresses forward in general heading
+        x = next.x
+        y = next.y
+        phase = next.currentPhase
+        history.push({ x, y })
+      }
+
+      // Check that lateral Y oscillates
+      const yValues = history.map((p) => p.y)
+      const minY = Math.min(...yValues)
+      const maxY = Math.max(...yValues)
+      expect(maxY - minY).toBeGreaterThan(10) // Demonstrated non-zero lateral sway
+    })
+
+    it('3.3 Armageddon: Drops meteors strictly within 8-yard radial boundary of Druid', () => {
+      const druidX = 500
+      const druidY = 500
+
+      // Test multiple deterministic angles and radius ratios
+      for (let i = 0; i < 36; i++) {
+        const angle = (i * Math.PI * 2) / 36
+        const radiusRatio = (i % 10) / 10
+        const loc = calculateArmageddonImpactLocation(druidX, druidY, angle, radiusRatio, 8)
+
+        expect(loc.distanceYards).toBeLessThanOrEqual(8.0)
+        expect(loc.distanceYards).toBeGreaterThanOrEqual(0.0)
+      }
+    })
+  })
+
+  // =========================================================================
+  // Dimension 4: Invariants, DataRegistry, and SkillModule Integration
+  // =========================================================================
+  describe('Dimension 4: Invariants, DataRegistry, and SkillModule Integration', () => {
+    it('4.1 BATCH1_SKILLS length invariant = 38 is strictly preserved', () => {
+      const batch1Keys = Object.keys(BATCH1_SKILLS)
+      expect(batch1Keys.length).toBe(38)
+    })
+
+    it('4.2 All 10 Druid Elemental skills are properly registered in SkillModule architecture', async () => {
+      const elementalIds = [225, 229, 230, 234, 235, 240, 244, 245, 249, 250]
+      const { skillModule: m225 } = await import('../../../src/game/skills/impl/dru/skill-225-firestorm.ts')
+      const { skillModule: m229 } = await import('../../../src/game/skills/impl/dru/skill-229-molten-boulder.ts')
+      const { skillModule: m230 } = await import('../../../src/game/skills/impl/dru/skill-230-arctic-blast.ts')
+      const { skillModule: m234 } = await import('../../../src/game/skills/impl/dru/skill-234-eruption.ts')
+      const { skillModule: m235 } = await import('../../../src/game/skills/impl/dru/skill-235-cyclone-armor.ts')
+      const { skillModule: m240 } = await import('../../../src/game/skills/impl/dru/skill-240-twister.ts')
+      const { skillModule: m244 } = await import('../../../src/game/skills/impl/dru/skill-244-volcano.ts')
+      const { skillModule: m245 } = await import('../../../src/game/skills/impl/dru/skill-245-tornado.ts')
+      const { skillModule: m249 } = await import('../../../src/game/skills/impl/dru/skill-249-armageddon.ts')
+      const { skillModule: m250 } = await import('../../../src/game/skills/impl/dru/skill-250-hurricane.ts')
+
+      const modules = [m225, m229, m230, m234, m235, m240, m244, m245, m249, m250]
+      for (let i = 0; i < elementalIds.length; i++) {
+        const id = elementalIds[i]
+        const mod = modules[i]
+        expect(mod).toBeDefined()
+        expect(mod.skillId).toBe(id)
+        expect(mod.charClass).toBe('dru')
+      }
+    })
+
+    it('4.3 DataRegistry loads all 10 Druid elemental skills from Patch_D2.mpq with exact attributes', async () => {
+      const reg = await getSharedDataRegistry('samples/d2')
+
+      // Firestorm
+      const fs = reg.getSkillById(225)
+      expect(fs).toBeDefined()
+      expect(fs!.name).toBe('Firestorm')
+      expect(fs!.castOverlay).toBe('druid_fire_cast_1')
+      expect(fs!.delay).toBe('15')
+
+      // Molten Boulder
+      const mb = reg.getSkillById(229)
+      expect(mb).toBeDefined()
+      expect(mb!.name).toBe('Molten Boulder')
+      expect(mb!.srvMissile).toBe('moltenboulderemerge')
+      expect(mb!.delay).toBe('50')
+
+      // Arctic Blast
+      const ab = reg.getSkillById(230)
+      expect(ab).toBeDefined()
+      expect(ab!.name).toBe('Arctic Blast')
+      expect(ab!.srvStFunc).toBe(11)
+      expect(ab!.srvDoFunc).toBe(19)
+
+      // Cyclone Armor
+      const ca = reg.getSkillById(235)
+      expect(ca).toBeDefined()
+      expect(ca!.name).toBe('Cyclone Armor')
+      expect(ca!.auraState).toBe('cyclonearmor')
+
+      // Twister
+      const tw = reg.getSkillById(240)
+      expect(tw).toBeDefined()
+      expect(tw!.name).toBe('Twister')
+      expect(tw!.srvMissileA).toBe('twister')
+
+      // Tornado
+      const tor = reg.getSkillById(245)
+      expect(tor).toBeDefined()
+      expect(tor!.name).toBe('Tornado')
+      expect(tor!.srvMissileA).toBe('tornado')
+
+      // Armageddon
+      const arm = reg.getSkillById(249)
+      expect(arm).toBeDefined()
+      expect(arm!.name).toBe('Armageddon')
+      expect(arm!.auraState).toBe('armageddon')
+      expect(arm!.delay).toBe('150')
+
+      // Hurricane
+      const hurr = reg.getSkillById(250)
+      expect(hurr).toBeDefined()
+      expect(hurr!.name).toBe('Hurricane')
+      expect(hurr!.auraState).toBe('hurricane')
+      expect(hurr!.delay).toBe('150')
+    })
+
+    it('4.4 evaluateSkill113c evaluates Druid elemental skills against StatList with exact cooldown & mana', async () => {
+      const reg = await getSharedDataRegistry('samples/d2')
+      const stats = new UnitStatList()
+
+      // Evaluate Firestorm
+      const fsRes = evaluateSkill113c({
+        registry: reg,
+        skill: reg.getSkillById(225)!,
+        slvl: 5,
+        blvl: 5,
+        statList: stats,
+      })
+      expect(fsRes.manaCost).toBe(4)
+      expect(fsRes.cooldownFrames).toBe(15)
+
+      // Evaluate Molten Boulder
+      const mbRes = evaluateSkill113c({
+        registry: reg,
+        skill: reg.getSkillById(229)!,
+        slvl: 10,
+        blvl: 10,
+        statList: stats,
+      })
+      expect(mbRes.manaCost).toBe(14)
+      expect(mbRes.cooldownFrames).toBe(50)
+
+      // Evaluate Hurricane
+      const hurrRes = evaluateSkill113c({
+        registry: reg,
+        skill: reg.getSkillById(250)!,
+        slvl: 20,
+        blvl: 20,
+        statList: stats,
+      })
+      expect(hurrRes.manaCost).toBe(30)
+      expect(hurrRes.cooldownFrames).toBe(150)
+    })
+  })
+})