Toph, the First Metalbender, Haru, Hidden Talent, Firdoch Core, and Phantom Train

Prerequisites

• Toph, the First Metalbender on the battlefield
• Haru, Hidden Talent on the battlefield
• Firdoch Core in hand
• Phantom Train on the battlefield
• available

Steps

1. Cast Firdoch Core by paying
2. When Firdoch Core enters, Haru triggers, earthbending Firdoch Core, as it's a land due to Toph
3. Activate Phantom Train by sacrificing Firdoch Core
4. When Firdoch Core dies, Haru triggers, returning Firdoch Core from your graveyard to the battlefield
5. When Firdoch Core enters, Haru triggers, earthbending Firdoch Core, as it's a land due to Toph
6. Resolve the Phantom Train ability
7. Repeat from step 3

Results

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