All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Alley Evasion

Choose one —
• Target creature you control gets +1/+2 until end of turn.
• Return target creature you control to its owner's hand.

Arm the Cathars

Until end of turn, target creature gets +3/+3, up to one other target creature gets +2/+2, and up to one other target creature gets +1/+1. Those creatures gain vigilance until end of turn.

Adamant Will

Target creature gets +2/+2 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Archivist of Oghma

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

Arborea Pegasus

Flying
When Arborea Pegasus enters the battlefield, target creature gets +1/+1 and gains flying until end of turn.

Akoum Hellkite

Flying
Landfall — Whenever a land enters the battlefield under your control, Akoum Hellkite deals 1 damage to any target. If that land is a Mountain, Akoum Hellkite deals 2 damage instead.

Act on Impulse

Exile the top three cards of your library. Until end of turn, you may play cards exiled this way. (If you cast a spell this way, you still pay its costs. You can play a land this way only if you have an available land play remaining.)

Have

Pinkie Pie

Whenever you cast a spell with a smile in its art, create a tapped Treasure token.
Everypony's Invited — Your party consists of each creature you control, and your party is always full.

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Arcane Signet

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

Adult Gold Dragon

Abbot of Keral Keep

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Abbot of Keral Keep enters the battlefield, exile the top card of your library. Until end of turn, you may play that card.

Baeloth Barrityl, Entertainer

Creatures your opponents control with power less than Baeloth Barrityl's power are goaded. (They attack each combat if able and attack a player other than you if able.)
Whenever a goaded attacking or blocking creature dies, you create a Treasure token.
Choose a Background (You can have a Background as a second commander.)