The Immortal
Identity — Guardian (U)
Undercover (Unveil only if another identity has been unveiled or if another player attacked the Leader this game.)
Unveil {3} (Start the game with this identity face down in the command zone. Turn it face up any time for its unveil cost.)
When The Immortal is unveiled, up to one target player gains 15 life and up to one target player shuffles their graveyard into their library.