Scatter Brain

Cascade (When you cast this spell, exile cards from
the top of your library until you exile a nonland card
whose converted mana cost is less than this spell's converted mana cost. You may cast that card without paying its mana cost. Then put all cards exiled this
way that weren't cast on the bottom of your library in
a random order.)
Target player sends the top 4 cards of their
library into their graveyard.