Danitha, Benalia's Hope, Yahenni, Undying Partisan, and Necrogen Communion

Prerequisites

• Danitha, Benalia's Hope on the battlefield
• Yahenni, Undying Partisan on the battlefield
• Necrogen Communion on the battlefield
• Necrogen Communion attached to Danitha

Steps

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

Results

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