CurseMarks/CurseMarks

I was thinking of trying to recreate a curse mark like Saskues in Naruto. Im trying to be not cheesy and add some different things to it (like making them out of soulsteel or something) im just not really sure how to make it so that its not totally overpowering. An idea I had was to give it a some sort of Limit Break that was partially controlled and to make it cost a certain amount of willpower to resist once your anima banner goes iconic. Heres what I have so far;

Curse Seal Release Level 1

Cost:10 motes
Minimums:(?????) 3, Essence 2
Type:Simple (Speed 3 combat time)
Kewords: Shaping, Obvious
Duration: One scene
Prerequisite: None

Calling forth a fraction of the power from the countless souls trapped inside their bodies in a powerful surge of tainted essence the Deathknight becomes capable of terrible attrocities. The Deathknight increase the accuracy of their favored weapon by one with a plus one bonus to unarmed attacks as well. All damage is increased by two and the Exalt may parry lethal attacks unarmed without a stunt for the rest of the scene. This charm pushes the Deathknights anima banner to the 11-15 level until the charm ends.