Rise of the Witch-king

Each player sacrifices a creature of their choice. If you sacrificed a creature this way, you may return another permanent card from your graveyard to the battlefield.

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.

Bombadil's Song

Target creature you control gets +1/+1 and gains hexproof until end of turn. The Ring tempts you. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Dúnedain Rangers

Landfall — Whenever a land you control enters, if you don't control a Ring-bearer, the Ring tempts you.

Tireless Provisioner

Landfall — Whenever a land you control enters, create a Food token or a Treasure token. (Food is an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life." Treasure is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sméagol, Helpful Guide

At the beginning of your end step, if a creature died under your control this turn, the Ring tempts you.
Whenever the Ring tempts you, target opponent reveals cards from the top of their library until they reveal a land card. Put that card onto the battlefield tapped under your control and the rest into their graveyard.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, you may create a 4/4 green Beast creature token.

Sam's Desperate Rescue

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

Cankerbloom

{1}, Sacrifice Cankerbloom: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

One Ring to Rule Them All

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — The Ring tempts you, then each player mills cards equal to your Ring-bearer's power.
II — Destroy all nonlegendary creatures.
III — Each opponent loses 1 life for each creature card in that player's graveyard.

Spelunking

When Spelunking enters, draw a card, then you may put a land card from your hand onto the battlefield. If you put a Cave onto the battlefield this way, you gain 4 life.
Lands you control enter untapped.

Claim the Precious

Destroy target creature. The Ring tempts you.

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.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.