Altaïr Ibn-La'Ahad + Éomer, Marshal of Rohan + Leyline of Transformation + Exalted Sunborn

Altaïr Ibn-La'Ahad

Éomer, Marshal of Rohan

Leyline of Transformation

Exalted Sunborn

How it works

1. Declare Altaïr as an attacker, triggering its ability, exiling Éomer from your graveyard with a memory counter on it and creating two tapped and attacking copies of Éomer.
2. Put all but one Éomer token into your graveyard due to the legend rule, causing you to get at least one Éomer trigger, causing you to untap all creatures you control and to get an additional combat phase after this one.
3. At the end of your combat phase, Altaïr triggers, causing you to exile the Éomer token.
4. Repeat each combat phase.

This clever loop turns Altaïr Ibn-La'Ahad into a one-man army by using Leyline of Transformation to ensure every creature you own—including Éomer, Marshal of Rohan—counts as an Assassin while in your graveyard. When Altaïr attacks, he exiles Éomer to spawn a copy, and thanks to Exalted Sunborn's replacement effect doubling your token creation, you actually get two attacking Éomer tokens instead of just one. The Legend Rule immediately sends one to the graveyard, triggering its ability to untap your board and grant you an additional combat phase. Since the remaining token vanishes at end of combat, you can simply repeat this process across infinite combats to continually trigger your creatures' enter-the-battlefield, leave-the-battlefield, and death effects!