Ephira, Veil of heaven

Flying, lifelink

Whenever you gain life, put a +1/+1 counter on Ephira,
Veil of Heaven.

As long as Ephira has five or more +1/+1 counters on it,
Ephira has hexproof and toxic 2 (Players dealt combat
damage by this creature also get two poison counters.)

Remove five +1/+1 counters from Ephira: Exile target
permanent.