Agatha's Soul Cauldron + Grist, the Hunger Tide + Grumgully, the Generous

Agatha's Soul Cauldron

Grist, the Hunger Tide

Grumgully, the Generous

How it works

1. Activate a creature using Grist's first loyalty ability by putting a loyalty counter on it, causing you to create a 1/1 Insect creature token and mill a card, and then put a loyalty counter on the creature and repeat the process if the card was an Insect.
2. The Insect enters the battlefield with a +1/+1 counter on it due to Grumgully, causing it to have Grist's abilities.
3. Repeat from step 1 using the Insect token instead.

This clever loop uses Agatha's Soul Cauldron to feed Grist, the Hunger Tide's loyalty ability to your creature tokens, turning them into self-replicating engines. Because Grumgully, the Generous ensures that every new Insect enters the battlefield with a +1/+1 counter, the Cauldron immediately grants it Grist's activated ability the moment it hits the board. You can then tap the newly minted Insect to activate Grist's ability again, milling your deck and generating another token to repeat the cycle indefinitely.