Altaïr Ibn-La'Ahad | Bloodthirster | Leyline of Transformation

Cards

Bloodthirster in your graveyard.
Altaïr Ibn-La'Ahad and
Leyline of Transformation on the battlefield (
Leyline of Transformation with "Assassin" chosen).
An opponent cannot block creatures you control.
You have a way to give
Altaïr Ibn-La'Ahad vigilance.

Give
Altaïr Ibn-La'Ahad vigilance by any method.
Declare
Altaïr Ibn-La'Ahad as an attacker.
Altaïr Ibn-La'Ahad triggers, exiling
Bloodthirster from your graveyard with a memory counter on it as it is an Assassin due to
Leyline of Transformation, and then creating a tapped and attacking token copy of each creature you own in exile with a memory counter on it.
Deal combat damage to an opponent using the
Bloodthirster token.
The
Bloodthirster token triggers, causing you to untap it and to get an additional combat phase after this one.
At the end of your combat phase,
Altaïr Ibn-La'Ahad triggers, exiling the
Bloodthirster token.
Move to your next combat phase, and declare
Altaïr Ibn-La'Ahad as an attacker.
Altaïr Ibn-La'Ahad triggers, creating a tapped and attacking token copy of each creature you own in exile with a memory counter on it.
Repeat from step 4.