Volrath, the Shapestealer

Mana cost: {2}{B}{G}{U}

Legendary Creature — Phyrexian Shapeshifter

At the beginning of combat on your turn, put a -1/-1 counter on up to one target creature. {1}: Until your next turn, Volrath becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.