Altar of Hades

(Altar of Hades is black.)
Whenever a creature dies you may create a 2/2
black hound creature token with menace. Then
put a devotion counter on to Altar of Hades.
At the beginning of each end step if Altar of
Hades has 3 or more devotion counters you may sacrifice all Hound creature tokens you control.
If you do you may exile this card and return it to
play transformed under your control.