Abigale, Eloquent First-Year

Flying, first strike, lifelink
When Abigale enters, up to one other target creature loses all abilities. Put a flying counter, a first strike counter, and a lifelink counter on that creature.

Angel of Finality

Flying
When this creature enters, exile target player's graveyard.

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Accursed Marauder

When this creature enters, each player sacrifices a nontoken creature of their choice.

All-Fates Stalker

When this creature enters, exile up to one target non-Assassin creature until this creature leaves the battlefield.
Warp {1}{W} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Seasoned Cathar

Ambitious Farmhand

When this creature enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
Coven — {1}{W}{W}: Transform this creature. Activate only if you control three or more creatures with different powers.

Ambitious Farmhand // Seasoned Cathar

Aerial Extortionist

Flying
Whenever this creature enters or deals combat damage to a player, exile up to one target nonland permanent. For as long as that card remains exiled, its owner may cast it.
Whenever another player casts a spell from anywhere other than their hand, draw a card.

Syr Vondam, Sunstar Exemplar

Vigilance, menace
Whenever another creature you control dies or is put into exile, put a +1/+1 counter on Syr Vondam and you gain 1 life.
When Syr Vondam dies or is put into exile while its power is 4 or greater, destroy up to one target nonland permanent.

Agent of Erebos

Constellation — Whenever this creature or another enchantment you control enters, exile target player's graveyard.

Abdel Adrian, Gorion's Ward

When Abdel Adrian enters, exile any number of other nonland permanents you control until Abdel Adrian leaves the battlefield. Create a 1/1 white Soldier creature token for each permanent exiled this way.
Choose a Background (You can have a Background as a second commander.)