Altar of Hera

(Altar of Hera is white.)
Whenever a creature enters the battlefield you
gain 2 life. Then you may put a devotion counter
on Altar of Hera.
At the beginning of each end step if there are
5 or more devotion counters on Altar of Hera you
may exile a creature you control. If you do exile
Altar of Hera and return it to the battlefield transformed under your control.