Yleroth the Trickster

Ward -{2}

When Yleroth attacks, you may exile a creature card from a graveyard with a collection counter on it. If
you do, put a number of +1/+1 counters on Yleroth equal to the power of the exiled card.

Yleroth has the abilities of all cards in exile with a collection counter on them that were exiled by a source you control.