Obliviator Reanimus

This card cannot be played from your hand.
{t}: Put a +2/+1 counter on artifact creatures you control.
Any time this card is in your graveyard you
may pay {7}. If you do, put it into play. It gains
haste and double strike until end of turn.
Exile Obliviator Reanimus: Add {7} to your
mana pool.