Szarel, Genesis Shepherd, Puppeteer Clique, and Hammerhead, Maggia Boss

Prerequisites

• Szarel, Genesis Shepherd on the battlefield
• Puppeteer Clique on the battlefield
• Hammerhead, Maggia Boss on the battlefield

Steps

1. Activate Hammerhead by sacrificing Puppeteer Clique
2. When Puppeteer Clique dies, its persist ability and Szarel trigger
3. Resolve the persist trigger, returning Puppeteer Clique from your graveyard to the battlefield with a -1/-1 counter on it
4. When Puppeteer Clique enters, it triggers, putting a creature card from an opponent's graveyard onto the battlefield under your control
5. Resolve the Szarel trigger, putting a number of +1/+1 counters on another creature you control
6. Resolve the Hammerhead ability from step 1
7. Activate Hammerhead by sacrificing the creature returned in step 4
8. When the creature dies, Szarel triggers, putting a number of +1/+1 counters on Puppeteer Clique
9. Resolve the Hammerhead ability
10. Repeat

Results

• Infinite +1/+1 counters on creatures you control
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers