Toph, the First Metalbender, Haru, Hidden Talent, Firdoch Core, and Phyrexian Altar

Prerequisites

• Toph, the First Metalbender on the battlefield
• Haru, Hidden Talent on the battlefield
• Firdoch Core in hand
• Phyrexian Altar 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 Phyrexian Altar 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. Repeat from step 3

Results

• Infinite LTB
• Infinite colored mana
• Infinite death triggers
• Infinite landfall triggers
• Infinite sacrifice triggers