Seebo, Trained Chaos

0: Exile the top card of your library. You may cast it this turn. If you do, put a loyalty counter on Seebo, Trained Chaos.
-3: The next spell you cast this turn has cascade. You may cast spells from exile this turn.
-X: Until the end of the turn, you may cast any number of exiled spells with converted mana cost half X without paying their mana costs.