Finn, The Undaunted

Vigilance
Discard a card: Exile Finn, return him to the battlefield under his owners control. Each time
you activate this ability per turn, increase the
discard cost by 1. At the beginning of each end
step, if you didn't use this ability this turn put
a +1/+1 counter on Finn.
Discard 3 cards: Finn is unlockable this turn.
If you don't have 3, discard your hand.