Scavenge the Boneheaps

(You may cast a legendary instant only if you control
a legendary creature or planeswalker.)
Until end of turn, you may cast cards from your
opponents' graveyards. You may spend mana as
though it were mana of any color to cast spells
this way. If a card would be put into a graveyard
this turn, exile it instead.
Exile Scavenge the Boneheaps