Sauron's Ring

{p/r}, Equip. Equipped creature gets +2/+0, deathtouch and shroud.
At the end of combat, if creatures retreated, you may select one creature that retreated and return them
to your side of the field under your control.

If the ring is destroyed or lost. phase all creatures controlled by the ring out of the game.

"One Ring to rule them all, One Ring to find them,
One Ring to bring them all, and in the darkness bind them" - Sauron