Aurelion Sol, Star Forger

Flying
Whenever a creature an opponent controls is
affected by an instant or sorcery you control,
you gain an experience counter.
{u}{u}{r}{r}{w}{w}{t}: The Skys Decend— Aurelion Sol deals X damage divided as you choose among any number of target creatures where X is equal to
the number of experience counters you have.
Aurelion Sol then deals damage to each opponent
equal to the number of creatures under
their control that have died this turn.