Aragorn, King of Gondor

Vigilance, lifelink
When Aragorn, King of Gondor enters, you become the monarch.
Whenever Aragorn attacks, up to one target creature can't block this turn. If you're the monarch, creatures can't block this turn.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Throne of the High City

{T}: Add {C}.
{4}, {T}, Sacrifice Throne of the High City: You become the monarch.

Skyline Despot

Flying
When Skyline Despot enters, you become the monarch.
At the beginning of your upkeep, if you're the monarch, create a 5/5 red Dragon creature token with flying.

Reprieve

Return target spell to its owner's hand.
Draw a card.

Archon of Coronation

Flying
When Archon of Coronation enters, you become the monarch.
As long as you're the monarch, damage doesn't cause you to lose life. (When a creature deals combat damage to you, its controller still becomes the monarch.)

Palace Jailer

When Palace Jailer enters, you become the monarch.
When Palace Jailer enters, exile target creature an opponent controls until an opponent becomes the monarch.

Faramir, Steward of Gondor

Whenever a legendary creature you control with mana value 4 or greater enters, you become the monarch.
At the beginning of your end step, if you're the monarch, create two 1/1 white Human Soldier creature tokens.

Keeper of Keys

When Keeper of Keys enters, you become the monarch.
At the beginning of your upkeep, if you're the monarch, creatures you control can't be blocked this turn.

Archivist of Gondor

When your commander deals combat damage to a player, if there is no monarch, you become the monarch.
At the beginning of the monarch's end step, that player draws a card.