Sighted-Caste Sorcerer

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{U}: Sighted-Caste Sorcerer gains shroud until end of turn. (It can't be the target of spells or abilities.)

Nimble Mongoose

Shroud (This creature can't be the target of spells or abilities.)
Threshold — Nimble Mongoose gets +2/+2 as long as seven or more cards are in your graveyard.

Soothing of Sméagol

Return target nontoken creature to its owner's hand. The Ring tempts you.

Rohirrim Lancer

Menace (This creature can't be blocked except by two or more creatures.)
When Rohirrim Lancer dies, the Ring tempts you.

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.)

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.

Highland Forest

({T}: Add {R} or {G}.)
Highland Forest enters tapped.

Took Reaper

When Took Reaper dies, the Ring tempts you.

Inherited Envelope

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

Breaking of the Fellowship

Target creature an opponent controls deals damage equal to its power to another target creature that player controls. The Ring tempts you.

Saiba Cryptomancer

Flash
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Hexproof

Uruk-hai Berserker

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

Naya Hushblade

As long as you control another multicolored permanent, Naya Hushblade gets +1/+1 and has shroud. (It can't be the target of spells or abilities.)

Enraged Huorn

Trample
When Enraged Huorn enters, the Ring tempts you.

Snow-Covered Mountain

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters tapped.

Boarding Party

Haste
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Snow-Covered Forest

Relentless Rohirrim

When Relentless Rohirrim enters, the Ring tempts you.

Snow-Covered Island

Stalwarts of Osgiliath

When Stalwarts of Osgiliath enters, the Ring tempts you.
Whenever you draw your second card each turn, put a +1/+1 counter on Stalwarts of Osgiliath.

Sam's Desperate Rescue

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

Silhana Ledgewalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Silhana Ledgewalker can't be blocked except by creatures with flying.

Skred

Skred deals damage to target creature equal to the number of snow permanents you control.

Claim the Precious

Destroy target creature. The Ring tempts you.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

Bountiful Landscape

{T}: Add {C}.
{T}, Sacrifice Bountiful Landscape: Search your library for a basic Forest, Island, or Mountain card, put it onto the battlefield tapped, then shuffle.
Cycling {G}{U}{R} ({G}{U}{R}, Discard this card: Draw a card.)

Slip On the Ring

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

Jolrael's Centaur

Shroud (This creature can't be the target of spells or abilities.)
Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Mirrormere Guardian

When Mirrormere Guardian dies, the Ring tempts you.

Utopia Sprawl

Enchant Forest
As Utopia Sprawl enters, choose a color.
Whenever enchanted Forest is tapped for mana, its controller adds an additional one mana of the chosen color.

Arboreal Grazer

Reach
When Arboreal Grazer enters, you may put a land card from your hand onto the battlefield tapped.