Phantom Train, Sister Hospitaller, and Fiend Hunter

Prerequisites

• Phantom Train on the battlefield
• Sister Hospitaller on the battlefield
• Fiend Hunter in hand
• available

Steps

1. Cast Fiend Hunter by paying its mana cost
2. When Fiend Hunter enters, its first ability triggers, exiling Sister Hospitaller
3. Activate Phantom Train by sacrificing Fiend Hunter
4. When Fiend Hunter dies, its second ability triggers, returning Sister Hospitaller from exile to the battlefield
5. When Sister Hospitaller enters, it triggers, returning Fiend Hunter from your graveyard to the battlefield
6. When Fiend Hunter enters, its first ability triggers, exiling Sister Hospitaller
7. Resolve the Phantom Train ability
8. Repeat from step 3

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite +1/+1 counters on a creature
• Infinite lifegain
• Infinite lifegain triggers