Day's Undoing - (Foil): Magic Origins Magic 2010 Whenever you cast a spell

Whenever you cast a spell from exile or a land enters the battlefield under your control from exile

Target opponent reveals their hand

or enchanted by anything black

Activate only if creatures you control have total power 8 or greater

When that mana is spent to cast a red instant or sorcery spell

Day's Undoing - (Foil): Magic Origins Magic 2010 Whenever you cast a spellEach player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)