Gymbro's Haymaker

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 of your library in a random order. Then do it
again.)

Gymbro's Haymaker deals damage to each creature
your opponents control equal to the total mana value
of other spells you've cast this turn.