Groundshaker Sliver

Sliver creatures you control have trample. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Ranger's Firebrand

Ranger's Firebrand deals 2 damage to any target. The Ring tempts you.

Tempered Sliver

Sliver creatures you control have "Whenever this creature deals combat damage to a player, put a +1/+1 counter on it."

Demonic Tutor

Boromir, Warden of the Tower

Vigilance
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
Sacrifice Boromir, Warden of the Tower: Creatures you control gain indestructible until end of turn. The Ring tempts you.

Lord of the Nazgûl

Flying
Wraiths you control have protection from Ring-bearers.
Whenever you cast an instant or sorcery spell, create a 3/3 black Wraith creature token with menace. Then if you control nine or more Wraiths, Wraiths you control have base power and toughness 9/9 until end of turn.

Lazotep Sliver

Sliver creatures you control have afflict 2. (Whenever a creature with afflict 2 becomes blocked, defending player loses 2 life.)
Whenever a nontoken Sliver you control dies, amass Slivers 2. (Put two +1/+1 counters on an Army you control. It's also a Sliver. If you don't control an Army, create a 0/0 black Sliver Army creature token first.)

Took Reaper

When Took Reaper dies, the Ring tempts you.

Rukarumel, Biologist

As Rukarumel, Biologist enters, choose a creature type.
Slivers you control and nontoken creatures you control are the chosen type in addition to their other creature types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 1/1 colorless Sliver creature token.

Slip On the Ring

Exile target creature you own, then return it to the battlefield under your control. The Ring tempts you.

Ringsight

The Ring tempts you. Search your library for a card that shares a color with a legendary creature you control, reveal it, put it into your hand, then shuffle.

Nazgûl

Deathtouch
When Nazgûl enters, the Ring tempts you.
Whenever the Ring tempts you, put a +1/+1 counter on each Wraith you control.
A deck can have up to nine cards named Nazgûl.

Uruk-hai Berserker

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

Cleaving Sliver

Call of the Ring

At the beginning of your upkeep, the Ring tempts you.
Whenever you choose a creature as your Ring-bearer, you may pay 2 life. If you do, draw a card.

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.

Syphon Sliver

Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)

Sam's Desperate Rescue

Return target creature card from your graveyard to your hand. The Ring tempts you.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.