Arbiter Triptych

Exploit (When this creature enters the battlefield,
you may sacrifice a creature.)
Whenever you sacrifice a creature Arbiter
Triptych, deals 1 damage to each other creature.
Hope - At the end of each phase, if a
creature you control was dealt nonlethal damage
this turn, you may exile Triptych. If you do
return them to play under their owner's control
at the beginning of the next phase.