Chernomor

Chernomor cost {x} more to cast, where X is your
life total.
Vigilance, lifelink, immunity (can't be affected by
any spell or ability other than its own).
Chernomor attacks or blocks each combat if able.
"Immortality is my retribution for a life of slaughters.
Dull and tormented, I'm now a puppet awaiting for
redemption and peering for a prospect of rest."