Let the Galaxy Burn X5R
Let the Galaxy Burn

Sorcery

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.)

Let the Galaxy Burn deals X plus 2 damage to each creature that didn t enter the battlefield this turn.