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.

Coppercoat Vanguard

Each other Human you control gets +1/+0 and has ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Théoden, King of Rohan

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

Adeline, Resplendent Cathar

Vigilance
Adeline, Resplendent Cathar's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature enters the battlefield under your control, Warleader's Call deals 1 damage to each opponent.

Combat Celebrant

If Combat Celebrant hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Horn of Gondor

When Horn of Gondor enters the battlefield, create a 1/1 white Human Soldier creature token.
{3}, {T}: Create X 1/1 white Human Soldier creature tokens, where X is the number of Humans you control.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Éowyn, Shieldmaiden

First strike
At the beginning of combat on your turn, if another Human entered the battlefield under your control this turn, create two 2/2 red Human Knight creature tokens with trample and haste. Then if you control six or more Humans, draw a card.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Swords to Plowshares

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

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

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.

Lossarnach Captain

First strike
Whenever Lossarnach Captain or another Human enters the battlefield under your control, tap target creature an opponent controls.
At the beginning of your upkeep, create a 1/1 white Human Soldier creature token.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Forth Eorlingas!

Create X 2/2 red Human Knight creature tokens with trample and haste.
Whenever one or more creatures you control deal combat damage to one or more players this turn, you become the monarch.

Beregond of the Guard

Whenever Beregond of the Guard or another Human enters the battlefield under your control, creatures you control get +1/+1 and gain vigilance until end of turn.