Muldrotha the Returned

Whenever an opponent casts an artifact or enchantment spell, they lose 3 life and you gain 3
life.
Whenever an opponent casts an instant or sorcery spell, they put the top 2 cards of their library into
their graveyard and you draw 2 cards.
Whenever a creature enters under your
opponent's control, put a -1/-1 counter on that creature and put a +1/+1 counter on this creature.
Whenever a land enters under your opponent's control, tap a land they control.