Éomer, Marshal of Rohan, and Legion Loyalty

Prerequisites

• Éomer, Marshal of Rohan on the battlefield
• Legion Loyalty on the battlefield
• Éomer cannot be blocked and killed by an opponent
• You have at least three opponents

Steps

1. Declare Éomer as an attacker
2. Éomer's myriad ability triggers, creating at least two token copies of it tapped and attacking each other opponent
3. Put all Éomer tokens into your graveyard due to the legend rule
4. When the Éomer token(s) die, each Éomer token triggers, untapping all creatures you control and causing you to get an additional combat phase after this one
5. Repeat each combat phase

Results

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