Nero, Master Hunter

First Strike
When this creature enters the battlefield, give it +1/+1 for every 2 life spent to cast it.
If this creature battles a non-human creature, it gains Indestructible and Trample until end of turn.
If a non-human creature dies, this card gains +1/+1 until end of turn.
"You will not enjoy this... But I promise to make it quick."