Agatha's Soul Cauldron, Famished Paladin, and Overgrown Arch

Prerequisites

• Agatha's Soul Cauldron on the battlefield
• Famished Paladin on the battlefield
• Overgrown Arch in exile

Steps

1. Activate Famished Paladin using Overgrown Arch's first ability by tapping it, causing you to gain 1 life
2. Famished Paladin triggers, untapping itself
3. Repeat

Results

• Infinite lifegain
• Infinite lifegain triggers