Interpret the Signs

Scry 3, then reveal the top card of your library. Draw cards equal to that card's mana value. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Crimson Fleet Commodore

Trample
When Crimson Fleet Commodore enters, you become the monarch.

The Prismatic Piper

If The Prismatic Piper is your commander, choose a color before the game begins. The Prismatic Piper is the chosen color.
Partner (You can have two commanders if both have partner.)

Elvish Doomsayer

When Elvish Doomsayer dies, each opponent discards a card.

Omenspeaker

When Omenspeaker enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Wildheart Invoker

{8}: Target creature gets +5/+5 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Universal Solvent

{7}, {T}, Sacrifice Universal Solvent: Destroy target permanent.

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Maelstrom Colossus

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.)

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.

Sentinel Spider

Inspiring Roar

Put a +1/+1 counter on each creature you control.

Ninth Bridge Patrol

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on Ninth Bridge Patrol.

Radiant, Serra Archangel

Flying
Tap another untapped creature you control with flying: Radiant, Serra Archangel gains protection from the color of your choice until end of turn.
Partner (You can have two commanders if both have partner.)

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.)

Court of Bounty

When Court of Bounty enters, you become the monarch.
At the beginning of your upkeep, you may put a land card from your hand onto the battlefield. If you're the monarch, instead you may put a creature or land card from your hand onto the battlefield.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Azure Fleet Admiral

When Azure Fleet Admiral enters, you become the monarch.
Azure Fleet Admiral can't be blocked by creatures the monarch controls.