Scars of Phyrexia

Planeswalkers enter the battlefield with no loyalty
counters, and players can't activate planeswalkers' loyalty abilities.
Planeswalkers are creatures with power and
toughness equal to their mana value. Remove all loyalty counters from all planeswalkers.
Whenever a planeswalker deals damage, put a
+1/+1 counter on it and its controller gains life
equal to it's power.