Layla Hassan

First strike
When Layla Hassan enters and whenever one or more Assassins you control deal combat damage to a player, return target historic card from your graveyard to your hand.

Ezio, Blade of Vengeance

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever an Assassin you control deals combat damage to a player, draw a card.

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Basim Ibn Ishaq

Whenever you cast a historic spell, draw a card. Basim Ibn Ishaq can't be blocked this turn. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic.)
Whenever Basim Ibn Ishaq deals combat damage to a player, put a +1/+1 counter on it.

Bayek of Siwa

Double strike
During your turn, other historic creatures you control have double strike.
Disguise {1}{R}{W} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Cover of Darkness

As Cover of Darkness enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Ezio Auditore da Firenze

Menace
Assassin spells you cast have freerunning {B}{B}. (You may cast a spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Whenever Ezio deals combat damage to a player, you may pay {W}{U}{B}{R}{G} if that player has 10 or less life. When you do, that player loses the game.

Achilles Davenport

Freerunning {U}{B} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Menace (This creature can't be blocked except by two or more creatures.)
Other Assassins you control get +1/+1.

Ramses, Assassin Lord

Deathtouch
Other Assassins you control get +1/+1.
Whenever a player loses the game, if they were attacked this turn by an Assassin you controlled, you win the game.

Altaïr Ibn-La'Ahad

First strike
Whenever Altaïr Ibn-La'Ahad attacks, exile up to one target Assassin creature card from your graveyard with a memory counter on it. Then for each creature card you own in exile with a memory counter on it, create a tapped and attacking token that's a copy of it. Exile those tokens at end of combat.

Arno Dorian

Deathtouch
Other Assassins you control get +2/+0.
Disguise {B}{R} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Desmond Miles

Menace
Desmond Miles gets +1/+0 for each other Assassin you control and each Assassin card in your graveyard.
Whenever Desmond Miles deals combat damage to a player, surveil X, where X is the amount of damage it dealt to that player.

Aya of Alexandria

Menace, lifelink
Whenever a historic creature you control deals combat damage to a player, create a 1/1 black Assassin creature token with menace. (Artifacts, legendaries, and Sagas are historic.)