Blade, Mara-Struck

Blade enters the battlefield with a -1/-1 counter
for each life spent to cast him
Whenever you pay life, remove a -1/-1 counter
from Blade. Then, if there are no -1/-1 counters
on Blade, transform him.
{p/b}{p/g}: Blade gains deathtouch or lifelink
until end of turn. Activate only once per turn.