The Soul Stone

Enchant Planeswalker
Enchanted Planeswalker has: "-1: Exile target
creature and put a pocket counter on it. When
someone looses the game, put exiled creatures
with pocket counters into play under the loosing
player's control. That player gains life equal the
total converted mana cost of all of the cards with pocket counters on them that entered the battlefield under that player's control. "