Call Forth the Tempest (Borderless)

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.)Call Forth the Tempest deals damage to each creature your opponents control equal to the total mana value of other spells you've cast this turn.