Geralt, Slayer of Fiends

+2: Until end of turn, Geralt, Slayer of Fiends becomes a 5/5 Human Warrior with indestructible and deathtouch that's still a planeswalker.
+1: Create a green 4/5 legendary Horse token called Roach with haste and trample. Exile it at the beginning of your end step.
-8: Destroy all non-Human creatures