Sheoldred's Slayer

Compleated{p/b}(For every {p/b} paid with 2 life in this creature's mana cost, it enters the battlefield with a -1/-1 counter on it)
Toxic 2 (Whenever this creature deals combat damage to a player, that player gets 2 poison counters)
Whenever Sheoldred's Slayer deals combat damage to a player, that player sacrifices a creature.