Nighthil, the Corruptor

+1: Draw a card, then discard a card. Creature spells you cast cost one colorless mana less to cast until end of turn
-3: Put a -1/-1 counter on target creature. You gain control of it
-8: Create X X/X black, green, and blue Hydra creature tokens with deathtouch and haste, where X is your devotion to black, green, and blue