Mikaeus, the Unhallowed, Woodfall Primus, and Yahenni, Undying Partisan

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Woodfall Primus on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Woodfall Primus
2. When Woodfall Primus dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. When Woodfall Primus enters, it triggers, destroying a noncreature permanent
4. Resolve the Yahenni ability
5. Activate Yahenni by sacrificing Woodfall Primus
6. When Woodfall Primus dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
7. When Woodfall Primus enters, it triggers, destroying a noncreature permanent
8. Resolve the Yahenni ability
9. Repeat

Results

• Destroy any number of noncreature permanents
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Lock