Mistweaver Hydra

{t}: Exile a card from your hand face down.
{g}: Turn a face-down card exiled with
Mistweaver Hydra face up. Put X +1/+1
counters on Mistweaver Hydra, where X is that
card's converted mana cost.
{g}, Remove two +1/+1 counters from
Mistweaver Hydra: Prevent all combat damage
that other creatures would deal this turn.