Agatha's Soul Cauldron, Servant of Tymaret, and Fatestitcher

Prerequisites

• Agatha's Soul Cauldron on the battlefield
• Servant of Tymaret on the battlefield
• Fatestitcher in exile

Steps

1. Activate Servant of Tymaret using Fatestitcher's ability by tapping it, untapping another creature you control that has a +1/+1 counter on it
2. Activate the other creature using Fatestitcher's ability by tapping it, untapping Servant of Tymaret Servant of Tymaret triggers, causing each opponent to lose 1 life and you to gain that much life
3. Repeat

Results

• Infinite lifegain
• Infinite lifegain triggers
• Infinite lifeloss