Toph, the First Metalbender, Retreat to Emeria, Haru, Hidden Talent, and Lion's Eye Diamond

Prerequisites

• Toph, the First Metalbender on the battlefield
• Retreat to Emeria on the battlefield
• Haru, Hidden Talent on the battlefield
• Lion's Eye Diamond in hand

Steps

1. Cast Lion's Eye Diamond by paying its mana cost
2. When Lion's Eye Diamond enters, Retreat to Emeria triggers, creating a 1/1 Kor Ally creature token
3. When the Kor Ally enters, Haru triggers, earthbending Lion's Eye Diamond
4. Activate Lion's Eye Diamond by discarding your hand and sacrificing it
5. Haru triggers, returning Lion's Eye Diamond from your graveyard to the battlefield
6. Repeat from step 2

Results

• Infinite ETB
• Infinite colored mana
• Infinite creature tokens
• Infinite landfall triggers