Mikaeus, the Unhallowed, Scuzzback Marauders, and Yahenni, Undying Partisan

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Scuzzback Marauders on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Scuzzback Marauders
2. When Scuzzback Marauders dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Resolve the Yahenni ability
4. Activate Yahenni by sacrificing Scuzzback Marauders
5. When Scuzzback Marauders dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
6. Resolve the Yahenni ability
7. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers