Rat Devotee

At any time during your turn, you may sacrifice target creature you control and put Sacrifice counters on this card equal to the sacrificed creature's power and toughness combined.
Rat Devotee has toughness equal to one plus the number of Sacrifice counter on this card.
If at any point Rat Devotee has more than 99 Sacrifice counters on it, sacrifice Rat Devotee. If you do, create Arun, Ultimate God Of the Cosmos, a legendary 50/50 colorless Avatar creature token with flying and Eternal.