Aurelion Sol, the Star Dragon

Flying, haste
Suspend 1 —{3}{u/r}{u/r}
While Aurelion Sol is in exile, instant and sorcery
spells you cast cost {1} less to cast for each time
counter on Aurelion Sol.
At the end of your turn, exile Aurelion Sol. Put
a time counter on it for each time it has been
exiled this game.