The Black Breath

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

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

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.

Took Reaper

When Took Reaper dies, the Ring tempts you.

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Claim the Precious

Destroy target creature. The Ring tempts you.

Thieves' Tools

When Thieves' Tools enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equipped creature can't be blocked as long as its power is 3 or less.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Orzhov Signet

Slip On the Ring

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

Sam's Desperate Rescue

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

Mortify

Fog on the Barrow-Downs

Enchant creature
Enchanted creature is a Spirit and can't attack or block. (It loses all other creature types.)

Vault of Champions

Vault of Champions enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Shineshadow Snarl

As Shineshadow Snarl enters, you may reveal a Plains or Swamp card from your hand. If you don't, Shineshadow Snarl enters tapped.
{T}: Add {W} or {B}.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

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.

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.

Escape from Orthanc

Target creature gets +1/+3 and gains flying until end of turn. Untap it.

Now for Wrath, Now for Ruin!

Put a +1/+1 counter on each creature you control. They gain vigilance until end of turn. The Ring tempts you.

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.

Bilbo's Ring

During your turn, equipped creature has hexproof and can't be blocked.
Whenever equipped creature attacks alone, you draw a card and you lose 1 life.
Equip Halfling {1} ({1}: Attach to target Halfling you control. Equip only as a sorcery.)
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Frodo, Sauron's Bane

{W/B}{W/B}: If Frodo, Sauron's Bane is a Citizen, it becomes a Halfling Scout with base power and toughness 2/3 and lifelink.
{B}{B}{B}: If Frodo is a Scout, it becomes a Halfling Rogue with "Whenever this creature deals combat damage to a player, that player loses the game if the Ring has tempted you four or more times this game. Otherwise, the Ring tempts you."

Rebuff the Wicked

Counter target spell that targets a permanent you control.

Delney, Streetwise Lookout

Creatures you control with power 2 or less can't be blocked by creatures with power 3 or greater.
If an ability of a creature you control with power 2 or less triggers, that ability triggers an additional time.

Despark

Exile target permanent with mana value 4 or greater.

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.

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. Talisman of Hierarchy deals 1 damage to you.

Lost to Legend

Put target nonland historic permanent into its owner's library fourth from the top. (Artifacts, legendaries, and Sagas are historic.)

Reprieve

Return target spell to its owner's hand.
Draw a card.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Tainted Field

{T}: Add {C}.
{T}: Add {W} or {B}. Activate only if you control a Swamp.

Command Tower

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Sol Ring

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Behind the Scenes

Creatures you control have skulk. (They can't be blocked by creatures with greater power.)
{4}{W}: Creatures you control get +1/+1 until end of turn.

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Dark Ritual

The Battle of Bywater

Destroy all creatures with power 3 or greater. Then create a Food token for each creature you control. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Inherited Envelope

When Inherited Envelope enters, the Ring tempts you.
{T}: Add one mana of any color.

Uruk-hai Berserker

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

Fetid Heath

{T}: Add {C}.
{W/B}, {T}: Add {W}{W}, {W}{B}, or {B}{B}.

Courageous Resolve

Up to one target creature you control gains protection from each of your opponents until end of turn. Draw a card. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything controlled by those players.)
Fateful hour — If you have 5 or less life, you can't lose life this turn, you can't lose the game this turn, and your opponents can't win the game this turn.

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.