Prismari, the Inspiration + Return the Favor

Prismari, the Inspiration

Return the Favor

How it works

1. Cast any other instant or sorcery by paying its mana cost.
2. Holding priority, cast Return the Favor by paying its mana cost, targeting the instant or sorcery cast in step 1.
3. Return the Favor's storm ability triggers, creating at least one copy of Return the Favor targeting the original Return the Favor.
4. Resolve a copy of Return the Favor, copying Return the Favor targeting the original Return the Favor.
5. Repeat step 4.

This infinite storm loop relies entirely on Prismari, the Inspiration granting every instant and sorcery you cast the storm ability, including modal spells. When you cast Return the Favor as your second spell of the turn, Prismari, the Inspiration triggers to copy it, allowing you to use Return the Favor's first spree mode to copy the original spell. Because that copy targets the original Return the Favor itself, you can perpetually chain copies to generate infinite magecraft triggers.