O'kar Drest, Dragon Mystic

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)
O'kar Drest enters the battlefield with X +1/+1 counters on it.
When you cast a creature exiled by O'kar Drest, draw X cards.