The Warden

Defender, Lifelink, Guardian (This creature takes
damage in the form of -1/-1 counters)
As The Warden enters the battlefield, exile all
permanents until Warden of the Deep Dark
leaves the battlefield.
{p/b}: Remove 2 -1/-1 counters from The Warden.
{8}: Exile The Warden. Only your opponents can activate this ability and only as a sorcery.