Baraqiel, the Living Vessel

Whenever you gain life, put a +1/+1 counter on target creature you control.
If a creature you control were to have five or more +1/+1 counters on it, sacrifice Baraqiel, the Living Vessel.
Baraqiel was the first to fall, having a lack of respect for the power he commanded. Proving that Watchers were not complete in their wisdom or their immortality.