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.

Aven Courier

Flying
Whenever this creature attacks, choose a counter on a permanent you control. Put a counter of that kind on target permanent you control if it doesn't have a counter of that kind on it.

Millstone

Locket of Yesterdays

Spells you cast cost {1} less to cast for each card with the same name as that spell in your graveyard.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Sol Ring

Council of Advisors

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Lantern of Insight

Players play with the top card of their libraries revealed.
{T}, Sacrifice this artifact: Target player shuffles.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Take into Custody

Tap target creature. It doesn't untap during its controller's next untap step.

Arcane Signet

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

Akal Pakal, First Among Equals

At the beginning of each player's end step, if an artifact entered the battlefield under your control this turn, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Island

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Sol Talisman

Suspend 3—{1} (Rather than cast this card from your hand, pay {1} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
{T}: Add {C}{C}.