Sidisi, Regent of the Mire, Sister Hospitaller, Sky Hussar, and Yahenni, Undying Partisan

Prerequisites

• Sidisi, Regent of the Mire on the battlefield
• Sister Hospitaller in the graveyard
• Sky Hussar on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Sidisi by tapping it and sacrificing Sky Hussar, returning Sister Hospitaller from your graveyard to the battlefield
2. When Sister Hospitaller enters the battlefield, it triggers, returning Sky Hussar from your graveyard to the battlefield and causing you to gain 5 life
3. When Sky Hussar enters the battlefield, it triggers, untapping all creatures you control
4. Activate Yahenni by sacrificing Sister Hospitaller
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite lifegain triggers
• Infinite lifegain
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce