Wrathful Weapon

You grant the targeted weapon one of the following weapon special abilities: anarchic, axiomatic, holy, or unholy. If anarchic, this spell has the chaos descriptor; if axiomatic, the law descriptor; if holy, the good descriptor; and if unholy, the evil descriptor. If the caster attempts to place a special ability on a weapon that already has that special ability, the spell fails.

If a warpriest casts this spell on his sacred weapon, the duration doubles. Warpriests with unarmed strike as a sacred weapon can cast this spell on their unarmed strike.