Ulamog's Dreadsire, Thornbite Staff, and Yahenni, Undying Partisan

Prerequisites

• Ulamog's Dreadsire on the battlefield
• Thornbite Staff on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Ulamog's Dreadsire by tapping it, creating a 10/10 Eldrazi creature tokens
2. Activate Yahenni by sacrificing the Eldrazi token
3. When the Eldrazi token dies, Ulamog's Dreadsire triggers, untapping Ulamog's Dreadsire
4. Resolve the Yahenni ability
5. Repeat

Results

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