Whenever Altaïr 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.
Altaïr is a snowball aggro/tokens commander: fill your graveyard with Assassin (and other) creature cards, then attack each turn to bank one more card under a memory counter in exile and stamp out tapped, attacking copies of everything you've stored. Early turns set up the graveyard via self-mill and cheap creatures, then mid-game your attacks generate a wider and wider army that swings before exiling at end of combat.
Generates a growing board of attacking token copies for free every combat once you've banked creatures in exile
First strike lets the 3-mana commander attack and trade safely while building value
Recurs value out of the graveyard, so spot removal on individual creatures is recouped
Mardu colors give access to the best removal, recursion, and aggressive payoffs
Slow to start: the first few attacks bank only one card, so you need setup before the swarm is threatening
Relies on Altaïr connecting in combat—removing or blocking the commander shuts off the engine
Graveyard hate exiles your fuel before you can bank it under memory counters
Tokens vanish at end of combat, so you commit to attacking and can be punished by board wipes and fogs
Wants a deep Assassin/creature base, which can be a narrow tribe to fill out
Add evasion and untap enablers like Reconnaissance, Maze of Ith effects, and menace/trample anthems so Altaïr reliably connects and your tokens get through. Improve graveyard velocity with Faithless Looting, Entomb, and Stitcher's Supplier, and shore up the curve with efficient Mardu removal and a few extra-combat spells like Aggravated Assault to double up the engine. Finally, include protection (Lightning Greaves, Teferi's Protection) so a single removal spell doesn't reset your snowball.
Legendary Creature — Human Assassin
