fix(core): DK ToT off-hand strikes and Titan Grip for classless

- Item: 2H weapon subclass/inventory masks for strike spells (ToT / dual 2H).
- Player: allow SPELL_EFFECT_TITAN_GRIP through skill validation; clear TG on
  talent/spec reset only for warriors.
- PlayerStorage: sync m_canTitanGrip from spellbook before inventory load.
- Spell: treat Thassarian off-hand strike spells as OFF_ATTACK when DBC omits
  SPELL_ATTR3_REQUIRES_OFF_HAND_WEAPON.

src/server/game/Entities/Item/Item.cpp

@@ -898,7 +898,31 @@ bool Item::IsFitToSpellRequirements(SpellInfo const* spellInfo) const
 
         if (spellInfo->EquippedItemSubClassMask != 0)        // 0 == any subclass
         {
-            if ((spellInfo->EquippedItemSubClassMask & (1 << proto->SubClass)) == 0)
+            uint32 subclassMask = spellInfo->EquippedItemSubClassMask & (1 << proto->SubClass);
+            // Two-handers use *_2 subclasses; many strike spells only set one-hand bits (main or off hand).
+            if (!subclassMask && proto->Class == ITEM_CLASS_WEAPON && proto->InventoryType == INVTYPE_2HWEAPON)
+            {
+                if (Player const* player = GetOwner() ? GetOwner()->ToPlayer() : nullptr)
+                {
+                    if (player && IsEquipped() && GetBagSlot() == INVENTORY_SLOT_BAG_0 &&
+                        (GetSlot() == EQUIPMENT_SLOT_OFFHAND || GetSlot() == EQUIPMENT_SLOT_MAINHAND))
+                    {
+                        int32 pairedSubclass = -1;
+                        switch (proto->SubClass)
+                        {
+                            case ITEM_SUBCLASS_WEAPON_AXE2:    pairedSubclass = ITEM_SUBCLASS_WEAPON_AXE; break;
+                            case ITEM_SUBCLASS_WEAPON_MACE2:   pairedSubclass = ITEM_SUBCLASS_WEAPON_MACE; break;
+                            case ITEM_SUBCLASS_WEAPON_SWORD2:  pairedSubclass = ITEM_SUBCLASS_WEAPON_SWORD; break;
+                            case ITEM_SUBCLASS_WEAPON_EXOTIC2: pairedSubclass = ITEM_SUBCLASS_WEAPON_EXOTIC; break;
+                            default: break;
+                        }
+                        if (pairedSubclass >= 0)
+                            subclassMask = spellInfo->EquippedItemSubClassMask & (1 << pairedSubclass);
+                    }
+                }
+            }
+
+            if (!subclassMask)
                 return false;                               // subclass not present in mask
         }
     }
@@ -910,6 +934,25 @@ bool Item::IsFitToSpellRequirements(SpellInfo const* spellInfo) const
                 (spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_WEAPONMAINHAND) ||
                  spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_WEAPONOFFHAND)))
             return true;
+        // 2H in off-hand or main-hand: many spells only list 1H / generic inventory types.
+        if (proto->InventoryType == INVTYPE_2HWEAPON)
+        {
+            if (Player const* player = GetOwner() ? GetOwner()->ToPlayer() : nullptr)
+            {
+                if (player && IsEquipped() && GetBagSlot() == INVENTORY_SLOT_BAG_0)
+                {
+                    if (GetSlot() == EQUIPMENT_SLOT_OFFHAND &&
+                        ((spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_WEAPONOFFHAND)) ||
+                         (spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_WEAPON))))
+                        return true;
+                    if (GetSlot() == EQUIPMENT_SLOT_MAINHAND &&
+                        ((spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_WEAPONMAINHAND)) ||
+                         (spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_WEAPON)) ||
+                         (spellInfo->EquippedItemInventoryTypeMask & (1 << INVTYPE_2HWEAPON))))
+                        return true;
+                }
+            }
+        }
         else if ((spellInfo->EquippedItemInventoryTypeMask & (1 << proto->InventoryType)) == 0)
             return false;                                   // inventory type not present in mask
     }

src/server/game/Entities/Player/Player.cpp

@@ -3088,6 +3088,12 @@ bool Player::CheckSkillLearnedBySpell(uint32 spellId)
     if (!sWorld->getBoolConfig(CONFIG_VALIDATE_SKILL_LEARNED_BY_SPELLS))
         return true;
 
+    // Titan Grip (e.g. talent 46917) ties to warrior-only skill lines in DBC. Classless / cross-class
+    // characters must keep the spell; otherwise it is deleted on every login and 2H off-hand unequips.
+    if (SpellInfo const* si = sSpellMgr->GetSpellInfo(spellId))
+        if (si->HasEffect(SPELL_EFFECT_TITAN_GRIP))
+            return true;
+
     SkillLineAbilityMapBounds skill_bounds = sSpellMgr->GetSkillLineAbilityMapBounds(spellId);
     uint32 errorSkill = 0;
     for (SkillLineAbilityMap::const_iterator sla = skill_bounds.first; sla != skill_bounds.second; ++sla)
@@ -3773,8 +3779,8 @@ bool Player::resetTalents(bool noResetCost)
         _removeTalent(itr, GetActiveSpecMask());
     }
 
-    // xinef: remove titan grip if player had it set
+    // xinef: remove titan grip on warrior talent reset (other classes may use custom Titan Grip)
-    if (m_canTitanGrip)
+    if (IsClass(CLASS_WARRIOR, CLASS_CONTEXT_ABILITY) && m_canTitanGrip)
         SetCanTitanGrip(false);
     // xinef: remove dual wield if player does not have dual wield spell (shamans)
     if (!HasSpell(674) && CanDualWield())
@@ -15409,8 +15415,8 @@ void Player::ActivateSpec(uint8 spec)
         SetPower(POWER_MANA, 0); // Mana must be 0 even if it isn't the active power type.
     SetPower(pw, 0);
 
-    // xinef: remove titan grip if player had it set and does not have appropriate talent
+    // xinef: remove titan grip if warrior had it set and does not have appropriate talent (other classes may use Titan Grip from custom spells)
-    if (!HasTalent(46917, GetActiveSpec()) && m_canTitanGrip)
+    if (IsClass(CLASS_WARRIOR, CLASS_CONTEXT_ABILITY) && !HasTalent(46917, GetActiveSpec()) && m_canTitanGrip)
         SetCanTitanGrip(false);
     // xinef: remove dual wield if player does not have dual wield spell (shamans)
     if (!HasSpell(674) && CanDualWield())

src/server/game/Entities/Player/PlayerStorage.cpp

@@ -5525,6 +5525,21 @@ bool Player::LoadFromDB(ObjectGuid playerGuid, CharacterDatabaseQueryHolder cons
     // xinef: load mails before inventory, so problematic items can be added to already loaded mails
     _LoadMail(holder.GetPreparedResult(PLAYER_LOGIN_QUERY_LOAD_MAILS), holder.GetPreparedResult(PLAYER_LOGIN_QUERY_LOAD_MAIL_ITEMS));
 
+    // m_canTitanGrip is normally set when SPELL_EFFECT_TITAN_GRIP runs. After spellbook load, ensure the
+    // flag matches any known TG spell so 2H off-hand items validate before _LoadInventory (classless DK, etc.).
+    for (auto const& spellItr : m_spells)
+    {
+        if (!spellItr.second->Active || spellItr.second->State == PLAYERSPELL_REMOVED)
+            continue;
+        if (SpellInfo const* si = sSpellMgr->GetSpellInfo(spellItr.first))
+            if (si->HasEffect(SPELL_EFFECT_TITAN_GRIP))
+            {
+                SetCanTitanGrip(true);
+                UpdateTitansGrip();
+                break;
+            }
+    }
+
     _LoadInventory(holder.GetPreparedResult(PLAYER_LOGIN_QUERY_LOAD_INVENTORY), time_diff);
 
     // update items with duration and realtime

src/server/game/Spells/Spell.cpp

@@ -61,6 +61,34 @@
 #include "IVMapMgr.h"
 #include "VMapMgr2.h"
 
+namespace
+{
+// Threat of Thassarian off-hand strikes (all ranks). DBC often omits SPELL_ATTR3_REQUIRES_OFF_HAND_WEAPON,
+// so m_attackType would stay BASE_ATTACK and item/damage use the wrong hand (breaks dual 2H / Titan Grip).
+bool IsDKThassarianOffHandStrikeSpell(SpellInfo const* spellInfo)
+{
+    if (!spellInfo || spellInfo->SpellFamilyName != SPELLFAMILY_DEATHKNIGHT || spellInfo->DmgClass != SPELL_DAMAGE_CLASS_MELEE)
+        return false;
+
+    SpellInfo const* first = spellInfo->GetFirstRankSpell();
+    if (!first)
+        return false;
+
+    switch (first->Id)
+    {
+        case 66198: // Obliterate
+        case 66196: // Frost Strike
+        case 66216: // Plague Strike
+        case 66188: // Death Strike
+        case 66217: // Rune Strike
+        case 66215: // Blood Strike
+            return true;
+        default:
+            return false;
+    }
+}
+} // namespace
+
 extern pEffect SpellEffects[TOTAL_SPELL_EFFECTS];
 
 SpellDestination::SpellDestination()
@@ -591,7 +619,7 @@ Spell::Spell(Unit* caster, SpellInfo const* info, TriggerCastFlags triggerFlags,
     switch (m_spellInfo->DmgClass)
     {
         case SPELL_DAMAGE_CLASS_MELEE:
-            if (m_spellInfo->HasAttribute(SPELL_ATTR3_REQUIRES_OFF_HAND_WEAPON))
+            if (m_spellInfo->HasAttribute(SPELL_ATTR3_REQUIRES_OFF_HAND_WEAPON) || IsDKThassarianOffHandStrikeSpell(m_spellInfo))
                 m_attackType = OFF_ATTACK;
             else
                 m_attackType = BASE_ATTACK;