Intruder Alarm, Emmara, Soul of the Accord, and Opposition

Prerequisites

• Intruder Alarm on the battlefield
• Emmara, Soul of the Accord on the battlefield
• Opposition on the battlefield

Steps

1. Activate Opposition by tapping Emmara, targeting Emmara
2. Emmara triggers, creating a 1/1 Soldier creature token
3. The Soldier enters the battlefield, triggering Intruder Alarm, untapping all creatures
4. Resolve the Opposition ability, tapping Emmara
5. Emmara triggers, creating a 1/1 Soldier creature token
6. The Soldier enters the battlefield, triggering Intruder Alarm, untapping all creatures
7. Repeat

Results

• Infinite creature tokens
• Infinite ETB
• Infinite mana creatures you control can produce
• Infinite untap of all creatures