Prismari, the Inspiration + Twincast

Prismari, the Inspiration

Twincast

How it works

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