[Nyeriah]

Changes Proposed:

This PR proposes changes to:

• Core (units, players, creatures, game systems).
• Scripts (bosses, spell scripts, creature scripts).
• Database (SAI, creatures, etc).

While a player is mind controlled (reported for Chains of Kel'Thuzad in Naxxramas, but this is generic charm-AI behaviour), Player::UpdateCharmedAI picks between a primary and a secondary spell slot at random (m_charmAISpells[... + rnd], rnd = urand(0, 1)). Player::PrepareCharmAISpells can leave a lower rank of the same spell chain in the secondary slot, so a caster whose top damage comes from a single chain (Frostbolt, Shadow Bolt, etc.) casts a reduced rank roughly half the time.

The fix normalizes every cached charm-AI spell to the highest rank the player has actually learned, by walking its spell chain with GetNextSpellInChain + HasSpell at the end of PrepareCharmAISpells. Distinct spells stay distinct (different chains are never merged); only same-chain lower ranks collapse up to the max known rank. This mirrors TrinityCore's rank resolution in PlayerAI::VerifySpellCast, applied once to AC's existing cache rather than porting the whole SimpleCharmedPlayerAI system.

AI-assisted Pull Requests

• AI tools (e.g. Claude, ChatGPT, or similar) were used entirely or partially to prepare this pull request. If checked, specify which tools and models below.
  • Tools/models used: Claude Code (Opus 4.8)
• I have read and understood the AC guidelines for AI Agentic Engineering

Issues Addressed:

• Closes [Naxxramas] KT mind control uses lower spell ranks sometimes azerothcore/azerothcore-wotlk#26664

SOURCE:

The changes have been validated through:

• Video evidence, knowledge databases or other public sources (e.g forums, Wowhead, etc.)

Mind controlled players on retail cast the maximum rank of their spells. The rank-resolution approach mirrors TrinityCore's PlayerAI::VerifySpellCast, which walks the spell chain up to the highest known rank before casting.

Tests Performed:

• Tested in-game by the author.
• This pull request requires further testing and may have edge cases to be tested.

Builds and passes apps/codestyle/codestyle-cpp.py. The change only reuses symbols already present in the same function (sSpellMgr) plus the existing Player::HasSpell.

How to Test the Changes:

• This pull request can be tested by following the reproduction steps provided in the linked issue

1. Have a raid member run a spell rank watch addon.
2. Engage Kel'Thuzad (25-man) and reach phase 2; wait for Chains of Kel'Thuzad to mind control players.
3. Confirm the mind controlled players only cast maximum ranks (no low-rank alerts).

Known Issues and TODO List:

• The two-slot charm-AI selection design (primary/secondary) is left untouched; a fuller port of TrinityCore's SimpleCharmedPlayerAI could replace it later if desired.

[Nyeriah]

Retargeting to azerothcore/azerothcore-wotlk upstream.