Dauthi Embrace

{B}{B}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

The Black Breath

Creatures your opponents control get -1/-1 until end of turn. The Ring tempts you.

Gollum, Patient Plotter

When Gollum, Patient Plotter leaves the battlefield, the Ring tempts you.
{B}, Sacrifice a creature: Return Gollum from your graveyard to your hand. Activate only as a sorcery.

Traitor's Clutch

Target creature gets +1/+0, becomes black, and gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Took Reaper

When Took Reaper dies, the Ring tempts you.

Uruk-hai Berserker

When Uruk-hai Berserker enters, the Ring tempts you.

Claim the Precious

Destroy target creature. The Ring tempts you.

Samwise the Stouthearted

Flash
When Samwise the Stouthearted enters, choose up to one target permanent card in your graveyard that was put there from the battlefield this turn. Return it to your hand. Then the Ring tempts you.

Gollum's Bite

Target creature gets -2/-2 until end of turn.
{3}{B}, Exile Gollum's Bite from your graveyard: The Ring tempts you. Activate only as a sorcery.