The Vessel

Vigilance
Whenever the Vessel deals combat damage to a creature, you get an experience counter.
The vessel has +1/+1 for each experience counter
you have.
If the Vessel would die, you may instead have an opponent create a black spirit creature token
with power and toughness equal to the Vessel's current power and toughness. If you do, exile the Vessel until the token leaves the battlefield.