Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Spirit Mantle

Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.

Murder

Rogue's Passage

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

Night's Whisper

Tainted Field

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

Sejiri Glacier

Sejiri Glacier enters tapped.
{T}: Add {W}.

Sejiri Shelter

Target creature you control gains protection from the color of your choice until end of turn.

Sejiri Shelter // Sejiri Glacier

Fracture

Destroy target artifact, enchantment, or planeswalker.

Lurrus of the Dream-Den

Companion — Each permanent card in your starting deck has mana value 2 or less. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Lifelink
Once during each of your turns, you may cast a permanent spell with mana value 2 or less from your graveyard.

Sign in Blood

Target player draws two cards and loses 2 life.

Utter End

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Hero's Downfall

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.

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Doom Blade

Access Tunnel

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

Vexilus Praetor

Flash
Vigilance
Aegis of the Emperor — Commanders you control have protection from everything.

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Fellwar Stone

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

Sam's Desperate Rescue

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

Swamp

Orzhov Signet

Inherited Envelope

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

Expel the Interlopers

Choose a number between 0 and 10. Destroy all creatures with power greater than or equal to the chosen number.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Isolated Chapel

Isolated Chapel enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Slip On the Ring

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

Concealed Courtyard

Concealed Courtyard enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.

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.

Whispersilk Cloak

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

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Talisman of Hierarchy

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

Weathered Wayfarer

{W}, {T}: Search your library for a land card, reveal it, put it into your hand, then shuffle. Activate only if an opponent controls more lands than you.

Mortify

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Arcane Signet

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

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

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."

Claim the Precious

Destroy target creature. The Ring tempts you.

Prowler's Helm

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

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to 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.)

Lotho, Corrupt Shirriff

Whenever a player casts their second spell each turn, you lose 1 life and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Orzhov Basilica

Orzhov Basilica enters tapped.
When Orzhov Basilica enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Plains

Exotic Orchard

Disenchant

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Temple of Silence

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {B}.

Selfless Spirit

Flying
Sacrifice Selfless Spirit: Creatures you control gain indestructible until end of turn.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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}.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Uruk-hai Berserker

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

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.

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.

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as Conqueror's Flail is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Dauthi Trapper

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

Command Tower

Took Reaper

When Took Reaper dies, the Ring tempts you.

Selfless Savior

Sacrifice Selfless Savior: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Bastion Protector

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

Faramir, Field Commander

At the beginning of your end step, if a creature died under your control this turn, draw a card.
Whenever the Ring tempts you, if you chose a creature other than Faramir, Field Commander as your Ring-bearer, create a 1/1 white Human Soldier creature token.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Go for the Throat

Sol Ring

Fetid Heath

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

Despark

Exile target permanent with mana value 4 or greater.

Dark Ritual

You Cannot Pass!

Destroy target creature that blocked or was blocked by a legendary creature this turn.

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.

Slash the Ranks

Destroy all creatures and planeswalkers except for commanders.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Escape Tunnel

{T}, Sacrifice Escape Tunnel: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{T}, Sacrifice Escape Tunnel: Target creature with power 2 or less can't be blocked this turn.

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.