Aadesh, Djinn of Tyranny

Flying, deathtouch, haste
Whenever another creature you control dies, put
X +1/+1 counters on target noncreature artifact
or enchantment you control, where X is that
creature's mana value and it becomes a 0/0 Spirit creature in addition to its other types.
"My only regret is that once I've collected every
mortal soul, I will only have eternity to punish them
for my imprisonment."