Kelias's Thrall

When Kelias's Thrall enters the battlefield, if it
had a +1/+1 counter on it, each player discards
a card a random, then you may choose target
creature in target players graveyard with
converted mana cost {4} or greater, return that
creature to the battlefield under your control.
Undying (When it dies, if it had no +1/+1
counters on it, return it to the battlefield under
its owner's control with a +1/+1 counter on it.)