Merry, Esquire of Rohan

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

Théoden, King of Rohan

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

Éowyn, Lady of Rohan

At the beginning of combat on your turn, target creature gains your choice of first strike or vigilance until end of turn. If that creature is equipped, it gains first strike and vigilance until end of turn instead.
Equip abilities you activate cost {1} less to activate.

Dúnedain Blade

Equipped creature gets +2/+1.
Equip Human {1}
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Éomer of the Riddermark

Haste
Whenever Éomer of the Riddermark attacks, if you control a creature with the greatest power among creatures on the battlefield, create a 1/1 white Human Soldier creature token.

Mountain

East-Mark Cavalier

Vigilance
Whenever East-Mark Cavalier deals damage to a Goblin or Orc, destroy that creature.

Éomer, King of Rohan

Double strike
Éomer, King of Rohan enters with a +1/+1 counter on it for each other Human you control.
When Éomer enters, target player becomes the monarch. Éomer deals damage equal to its power to any target.

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.

Rohirrim Lancer

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

Riders of Rohan

When Riders of Rohan 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.)