Puppeteer Clique + Phyrexian Altar + Thran Vigil

Puppeteer Clique

Phyrexian Altar

Thran Vigil

How it works

1. Activate Phyrexian Altar by sacrificing Puppeteer Clique.
2. When Puppeteer Clique dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Thran Vigil and Puppeteer Clique trigger.
4. Resolve the Thran Vigil trigger, putting a +1/+1 counter on Puppeteer Clique.
5. Resolve the Puppeteer Clique trigger, allowing you to put a creature card from an opponent's graveyard onto the battlefield under your control.
6. Repeat.

This loop turns your opponents' graveyards into your personal staging ground while generating an endless supply of mana and triggers. By sacrificing Puppeteer Clique to Phyrexian Altar, you get a mana of any color while sending the Clique to the graveyard, which simultaneously causes it to leave your graveyard and triggers its persist ability. This graveyard departure triggers Thran Vigil to place a +1/+1 counter on Puppeteer Clique, which immediately cancels out the -1/-1 counter it receives when persist returns it to the battlefield. Because the counter is neutralized, persist can trigger again the next time it dies, allowing you to repeat the cycle indefinitely to drain every creature card out of your opponents' graveyards and reap infinite sacrifices.