Mewtwo, Mind's Destruction

Flying, trample, protection form instants
When Mewtwo, Mind's Destruction deals combat damage to a player, that player discards a card and
puts the top two cards of their library into their
graveyard.
{2}{u}{b}: Exile a card from a graveyard.
You may cast that card this turn and may spend
mana as though it where mana of any color to
cast that spell.