Sister Hospitaller, Phyrexian Altar, and Phantom Steed

Prerequisites

• Sister Hospitaller in hand
• Phyrexian Altar on the battlefield
• Phantom Steed in the graveyard
• available

Steps

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

Results

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