Danitha, Benalia's Hope, Unhallowed Pact, and Yahenni, Undying Partisan

Prerequisites

• Danitha, Benalia's Hope on the battlefield
• Unhallowed Pact on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Danitha
2. When Danitha dies, Unhallowed Pact triggers, returning Danitha from your graveyard to the battlefield tapped
3. When Danitha enters the battlefield, it triggers, returning Unhallowed Pact from your graveyard to the battlefield attached to Danitha
4. Resolve the Yahenni ability
5. Repeat

Results

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