Vixos, Lord of the Chain

Whenever a creature enters the battlefield under your control, if that creature has a -1/-1 counter on it, put two +1/+1 counters on it. It gains haste until end of turn.
Enslave {b}{r} (Whenever a creature dealt damage by Vixos, Lord of the Chain this turn dies, you may pay {b}{r}. If you do, return that creature to the battlefield tapped and with a -1/-1 counter on it.)