Nil, the End

Shadow, Ward —Discard a nonland card.
Whenever Nil, the End deals combat damage to
a player, choose one spell from your graveyard or
card you own in exile, then choose one spell from
that opponent's graveyard or card they own in
exile. Create a copy of each of those cards, then
shuffle them into their owner's libraries. You
may cast these copies, and you may spend mana
as though it were mana of any color to cast them.