Toph, the First Metalbender, Haru, Hidden Talent, Conspiracy, and Hammerhead, Maggia Boss

Prerequisites

• Toph, the First Metalbender on the battlefield
• Haru, Hidden Talent on the battlefield
• Conspiracy on the battlefield
• Hammerhead, Maggia Boss on the battlefield

Steps

1. Cast any artifact creature by paying its mana cost
2. When the artifact creature enters as an Ally due to Conspiracy, Haru triggers, earthbending the artifact creature, as it's a land due to Toph
3. Activate Hammerhead by sacrificing the artifact creature
4. When the creature dies, Haru triggers, returning the creature from your graveyard to the battlefield
5. When the creature enters as an Ally due to Conspiracy, Haru triggers, earthbending the creature, as it's a land due to Toph
6. Resolve the Hammerhead ability, putting a +1/+1 counter on Hammerhead
7. Repeat from step 3

Results

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