Sister Hospitaller, Phantom Train, and Lagrella, the Magpie Combo

Sister Hospitaller, Phantom Train, and Lagrella, the Magpie

Here's how the cards Sister Hospitaller, Phantom Train, and Lagrella, the Magpie results in Infinite LTB, Infinite ETB, Infinite sacrifice triggers, Infinite death triggers, Infinite lifegain triggers, Infinite lifegain, and Infinite +1/+1 counters on a creature

Sister Hospitaller

Phantom Train

Lagrella, the Magpie

Prerequisites

Sister Hospitaller in hand
Phantom Train on the battlefield
Lagrella, the Magpie in the graveyard
available

Steps

Cast Sister Hospitaller by paying
When Sister Hospitaller enters, it triggers, returning Lagrella from your graveyard to the battlefield and causing you to gain life equal to its mana value
When Lagrella enters, it triggers, exiling Sister Hospitaller until Lagrella leaves the battlefield
Activate Phantom Train by sacrificing Lagrella
When Lagrella leaves the battlefield, Sister Hospitaller is returned from exile to the battlefield
Repeat from step 2
Resolve all Phantom Train abilities