True Face Unseen

As an additional cost to cast True Face Unseen,
return a creature you control to its owner's hand.
You may put another creature card from your
hand onto the battlefield. If the returned
creature was attacking and unblocked, put that
card onto the battlefield tapped and attacking the
same player or planeswalker instead. Then
sacrifice it unless you pay the difference in mana
costs between it and the returned creature.
(Mana cost includes color.)