Gonti the Heartless

Gonti the Heartless enters the battlefield
with a number of +1/+1 counters on it equal
to the amount of mana spent to cast it.
At the beginning of your end step, remove a +1/+1 counter from Gonti.
{t}: Gonti deals damage equal to its power to target creature. If that creature dies this turn,
put a +1/+1 counter on Gonti.