Altaïr Ibn-La'Ahad, Éomer, Marshal of Rohan, Leyline of Transformation, and Primal Vigor

Prerequisites

• Altaïr Ibn-La'Ahad on the battlefield
• Éomer, Marshal of Rohan in the graveyard
• Leyline of Transformation on the battlefield
• Primal Vigor on the battlefield

Steps

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

Results

• Infinite LTB
• Infinite ETB
• Infinite death triggers
• Infinite combat phases
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce