The One Ring

Sauron, The Dark Lord gains a +5/+5 counter
and Indestructible when equipped.
If The One Ring is destroyed, Sauron, The Dark
Lord transforms into The Eye of Sauron until
The One Ring is reattached to Sauron. If The
One Ring is exiled, also exiled Sauron, The Dark
Lord, The Eye of Sauron, and all Nazgul in your
graveyard, hand and on the battlefield, lose half
of your life.
"One ring to rule them all."