Metastatic Evangel + Cloudstone Curio + Herd Baloth

Metastatic Evangel

Cloudstone Curio

Herd Baloth

How it works

1. Cast the creature by paying 0.
2. When the creature enters the battlefield, Metastatic Evangel triggers, and Cloudstone Curio triggers if the creature was not an artifact.
3. Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing to your hand.
4. Resolve the Metastatic Evangel trigger, causing you to put a +1/+1 counter on Herd Baloth.
5. Herd Baloth triggers, creating a 4/4 Beast creature token.
6. When the Beast enters the battlefield, Cloudstone Curio triggers, returning the creature with mana cost 0 from the battlefield to your hand.
7. Repeat.

This clever loop transforms free creature spells into an engine for infinite growth and token generation. By utilizing Cloudstone Curio to bounce a zero-mana creature whenever your token enters, you continuously reset your casting fodder while Metastatic Evangel triggers a proliferate effect. That proliferation drops a fresh +1/+1 counter onto Herd Baloth, which in turn answers with a 4/4 Beast token to trip the Curio all over again.