Creature with Mana Cost Equal to ({0} magic symbol)
Prerequisites
Creature with Mana Cost Equal to ({0} magic symbol) in hand.
All other permanents on the battlefield.
Herd Baloth has at least one +1/+1 counter on it.
Steps
Cast the creature by paying ({0} magic symbol) .
When the creature enters the battlefield, Metastatic Evangel triggers, and Cloudstone Curio triggers if the creature was not an artifact.
Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing to your hand.
Resolve the Metastatic Evangel trigger, causing you to put a +1/+1 counter on Herd Baloth.
Herd Baloth triggers, creating a 4/4 Beast creature token.
When the Beast enters the battlefield, Cloudstone Curio triggers, returning the creature with mana cost ({0} magic symbol) from the battlefield to your hand.