The Battles of Isen

(You may cast a legendary sorcery only if you
control a legendary creature or planeswalker.)
You may sacrifice a legendary creature or planeswalker you control. If you do, return all creatures and planeswalkers you don't control to
their owners' hands.
Rebound (If you cast this spell from your hand, exile
it as it resolves. At the beginning of your next upkeep,
you may cast this card from exile without paying its
mana cost.)