Try this. Also added registering the spell just in case you didn't.
oops guess you don't need this anymore posted as soon as you postedCode:function BlackhandAssassin_OnSpawn(Unit, Event) Unit:CastSpell(32199) end function Shadowtiger_OnEnterCombat(Unit, Event) unit:RegisterEvent("BlackhandAssassin_OnSpawn",1000, 0) end RegisterUnitEvent(65052, 1, "BlackhandAssassin_OnEnterCombat") RegisterUnitEvent(10318, 6, "BlackhandAssassin_OnSpawn")