Aida Ran, Furybound

Cascade, 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 in a random order. Then do it again.)
Aida Ran, Furybound can't be countered and enters the battlefield with X +1/+1 counters on her, where X is the number of spells that were cast this turn. If X is 3 or more, she gains Haste.