Kelwarin, "False" Hero

Whenever a creature dealt damage to by Kelwarin this turn dies, put a number of +1/+1 counters on Kelwarin equal to the mana value of the creature.

{b}{b}, Remove any number of +1/+1 counters from Kelwarin: Exile a creature card from a graveyard with mana value equal to the number of +1/+1 counters removed in this way. Create a token that's
a copy of it, except it is Black and is a Zombie in addition to its other types and colors.