Kha'Zix, the Voidreaver

Whenever a creature that was dealt damage
by Kha'Zix this turn dies, put a +1/+1 counter
on it.
Kha'Zix gains additional keywords and abilites
when he reaches certain power amounts —
•At 3; Kha'Zix gains first strike.
•At 5; Kha'Zix gains lifelink.
•At 7; Kha'Zix gains reach and "Whenever a
creature that was dealt damage by Kha'Zix this
turn dies, draw a card."