Forbidden Dance

Hideaway (When this card enters the battlefield, look
at the top four cards of your library, exile one with this
card, then put the rest on the bottom of your library.)
Pair up to two creatures you control. As long as
those creatures are paired, they get +0/+1 and
have undying.
When you no longer control a creature with
undying, sacrifice this card and put the card
exiled with Forbidden Dance into your hand.