Alibou, Ancient Witness

Other artifact creatures you control have haste.
Whenever one or more artifact creatures you control attack, Alibou, Ancient Witness deals X damage to any target and you scry X, where X is the number of tapped artifacts you control.

Automatic Librarian

When Automatic Librarian 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.)

Anarchist

When Anarchist enters, you may return target sorcery card from your graveyard to your hand.

Audacious Reshapers

{T}, Sacrifice an artifact: Reveal cards from the top of your library until you reveal an artifact card. Put that card onto the battlefield and the rest on the bottom of your library in a random order. Audacious Reshapers deals damage to you equal to the number of cards revealed this way.

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Ignacio of Myra's Marvels

As Ignacio of Myra's Marvels enters, choose armor, blood, book, bottle, fang, fire, scroll, spear, sword, or water.
Whenever you cast a spell with the chosen object in its art, create two Treasure tokens.
Partner (You can have two commanders if both have partner.)

Autograph Book

Autograph Book enters with a page counter on it for each person who has signed it.
{3}, {T}, Remove a page counter from Autograph Book: Draw a card.

Apostle's Blessing

({W/P} can be paid with either {W} or 2 life.)
Target artifact or creature you control gains protection from artifacts or from the color of your choice until end of turn.

Academic Dispute

Target creature blocks this turn if able. You may have it gain reach until end of turn.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Katerina of Myra's Marvels

As Katerina of Myra's Marvels enters, choose a letter.
Whenever you cast a spell whose name begins with the chosen letter, create a white 2/2 Cat creature token with flying.
Partner (You can have two commanders if they both have partner.)

Arcane Teachings

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets +2/+2 and has "{T}: This creature deals 1 damage to any target."