Combat Integration
FTK2.ModAPI 0.5.9 has direct runtime evidence for the native consumers that take a custom item ability from equipment to damage.
Equipment
InventoryController.CharacterEquip
→ EquipmentHelper.Equip
→ CharacterHelper.GetCharacterUseItemAbilities
The equipped Ember Axe enumerated Flame Cleave with its matching item SkillRollData.
Combat availability
CombatPhase
→ CombatHelper.GetAbilities
→ GetThingAbilities
→ CombatAbilitiesTemplateHelper.ShowButton
The native UI created a Flame Cleave action that was visible, enabled, and selectable.
Execution
CombatPhase
→ CombatHelper.PerformAbility
→ ApplyAction
→ InteractableHelper.ApplyStatChange
The accepted run correlated the same granting Thing, source, target, and HP change, then observed target health fall from 14 to 0.
These names document verified FTK2 1.14.6 integration boundaries. Consumer mods should use the public ICustomAbilityService and item APIs rather than patching these internal game methods as part of the normal authoring flow.