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.

Relentless Rohirrim

When this creature enters, the Ring tempts you.

Mountain

Éomer, Marshal of Rohan

Haste
Whenever one or more other attacking legendary creatures you control die, untap all creatures you control. After this phase, there is an additional combat phase. This ability triggers only once each turn.

Quarrel's End

As an additional cost to cast this spell, discard a card.
Draw two cards and create a 1/1 white Human Soldier creature token.

Shadowfax, Lord of Horses

Horses you control have haste. (They can attack and {T} as soon as they come under your control.)
Whenever Shadowfax attacks, you may put a creature card with lesser power from your hand onto the battlefield tapped and attacking.

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

Riders of Rohan

When this creature enters, create two 2/2 red Human Knight creature tokens with trample and haste.
Dash {4}{R}{W} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Éowyn, Fearless Knight

Haste
When Éowyn enters, exile target creature an opponent controls with greater power. Legendary creatures you control gain protection from each of that creature's colors until end of turn.

Esquire of the King

{4}{W}, {T}: Creatures you control get +1/+1 until end of turn. This ability costs {2} less to activate if you control a legendary creature.

Smite the Deathless

Smite the Deathless deals 3 damage to target creature. That creature loses indestructible until end of turn. If that creature would die this turn, exile it instead.

Westfold Rider

Sacrifice this creature: Destroy target artifact or enchantment. Activate only as a sorcery.

Merry, Esquire of Rohan

Haste
Merry has first strike as long as it's equipped.
Whenever you attack with Merry and another legendary creature, draw a card.

Gandalf, White Rider

Vigilance
Whenever you cast a spell, creatures you control get +1/+0 until end of turn. Scry 1.
When Gandalf dies, you may put it into its owner's library fifth from the top.

Erkenbrand, Lord of Westfold

Whenever Erkenbrand or another Human you control enters, creatures you control get +1/+0 until end of turn.

Banish from Edoras

This spell costs {2} less to cast if it targets a tapped creature.
Exile target creature.

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Rally at the Hornburg

Create two 1/1 white Human Soldier creature tokens. Humans you control gain haste until end of turn.

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.

Théoden, King of Rohan

Whenever Théoden or another Human you control enters, target creature gains double strike until end of turn.

Rohirrim Lancer

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

Gimli, Counter of Kills

Trample
Whenever a creature an opponent controls dies, Gimli deals 1 damage to that creature's controller.

East-Mark Cavalier

Vigilance
Whenever this creature deals damage to a Goblin or Orc, destroy that creature.

Lost to Legend

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

Plains

Errand-Rider of Gondor

When this creature enters, draw a card. Then if you don't control a legendary creature, put a card from your hand on the bottom of your library.

Minas Tirith

Minas Tirith enters tapped unless you control a legendary creature.
{T}: Add {W}.
{1}{W}, {T}: Draw a card. Activate only if you attacked with two or more creatures this turn.