Brutality

Imprint — , : You may exile an instant or sorcery card with mana value X from your hand. At the beginning of your upkeep, you may copy a card exiled with this artifact. If you do, you may cast the copy without paying its mana cost.

After the second main phase this turn, there's an additional combat phase followed by an additional main phase. At the beginning of that combat, untap all creatures that attacked this turn. 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.)