Szarel, Genesis Shepherd + Puppeteer Clique + Grimgrin, Corpse-Born

Szarel, Genesis Shepherd

Puppeteer Clique

Grimgrin, Corpse-Born

How it works

1. Activate Grimgrin 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 Grimgrin ability from step 1.
7. Activate Grimgrin 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 Grimgrin ability.
10. Repeat.