Echoes of Eternity

At the beginning of each player's upkeep, you may exile target creature you control.
If a creature is exiled this way, it gains a +1/+1 counter at the beginning of each upkeep while it remains exiled.
You may return a creature exiled with Echoes of Eternity to the battlefield at any time.
"In the endless abyss, even the faintest echoes can grow into titanic roars, returning to the world in an unstoppable force."