Dark Magic Curtain

Rebound (When cast from your hand, exile
it as it resolves. At the beginning of your
next upkeep, you may cast this from exile)
Play both commanders you own without paying
their mana cost by sacrificing up to two creatures
and paying the difference in life. If both are in
play reduce {2} from one of their commander tax
permanently instead.
"We will always return to defend our kingdom!"