Balefang the Unslayable [Mystery Booster: Commander Edition]

Flying, trample, protection from Angels and from Archons
Players can't gain life.
When Balefang enters, target opponent creates a tapped Baneslayer Angel token. The token is goaded for the rest of the game. (It's a 3WW 5/5 Angel creature with flying, first strike, lifelink, and protection from Demons and from Dragons.)