Monk Gyatso, Rakdos, Lord of Riots, and Umbral Mantle

Prerequisites

• Monk Gyatso on the battlefield
• Rakdos, Lord of Riots on the battlefield
• Umbral Mantle on the battlefield

Steps

1. Activate Umbral Mantle's equip ability by paying , targeting another nontoken creature you control
2. Monk Gyatso triggers, airbending the targeted creature
3. The Umbral Mantle ability fizzles due to no longer having a legal target
4. Cast the creature from exile by paying due to Rakdos
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite storm count