Sister Hospitaller, Ashnod's Altar, and Lumbering Battlement

Prerequisites

• Sister Hospitaller in hand
• Ashnod's Altar on the battlefield
• Lumbering Battlement in the graveyard
• available

Steps

1. Cast Sister Hospitaller by paying
2. When Sister Hospitaller enters, it triggers, returning Lumbering Battlement from your graveyard to the battlefield and causing you to gain life equal to its mana value
3. When Lumbering Battlement enters, it triggers, exiling Sister Hospitaller until Lumbering Battlement leaves the battlefield
4. Activate Ashnod's Altar by sacrificing Lumbering Battlement
5. When Lumbering Battlement leaves the battlefield, Sister Hospitaller is returned from exile to the battlefield
6. Repeat from step 2

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite colorless mana
• Infinite lifegain triggers
• Infinite lifegain