Xalvador, Tyrant of Virtaiya

Deathtouch
Creatures you control get -1/-1.
Whenever a creature dies, put a +1/+1 counter of Xalvador, Tyrant of Virtaiya.
If Xalvador, Tyrant of Virtaiya would die from a spell your opponents control, that spells controller becomes the Over-thrower.