Altaïr Ibn-La'Ahad + Éomer, Marshal of Rohan + Leyline of Transformation + Windcrag Siege
Altaïr Ibn-La'Ahad
Éomer, Marshal of Rohan
Leyline of Transformation
Windcrag Siege
Infinite creature LTBInfinite creature ETBInfinite death triggersInfinite combat phases
How it works
Declare Altaïr as an attacker, triggering its ability twice.
Resolve a Altaïr trigger, exiling Éomer from your graveyard with a memory counter on it and creating a tapped and attacking copy of Éomer.
Resolve the other Altaïr trigger, creating a tapped and attacking copy of Éomer.
Put either Éomer token into your graveyard due to the legend rule, triggering the other Éomer token, causing you to untap all creatures you control and to get an additional combat phase after this one.
At the end of your combat phase, Altaïr triggers, causing you to exile the Éomer token.