Hardy Haunter

Evolve Gastly {b}{b} ({b}{b}, Exile a Gastly you
control: Put this card onto the battlefield from your
hand. Haunter gets X +1/+1 counters, where X is
the exiled creatures power. Evolve only as a sorcery.)
Deathtouch (Any amount of damage this deals to a
creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes
you to gain that much life.)