Storm-Kiln Artist + Swarm Intelligence + Narset's Reversal

Prerequisites

You have another instant and/or sorcery card in hand that can be cast using four or less colored mana. You have enough mana to cast the additional instant or sorcery.

Steps

1. Cast any other instant or sorcery spell by paying its mana cost.
2. Swarm Intelligence and Storm-Kiln Artist trigger.
3. Resolve the Storm-Kiln Artist trigger, creating a Treasure artifact token.
4. Resolve the Swarm Intelligence trigger, copying the spell.
5. Storm-Kiln Artist triggers, creating a Treasure artifact token.
6. Resolve the copy of the instant or sorcery.
7. Holding priority, activate the Treasures by tapping and sacrificing them, adding {U}{U}.
8. Cast Narset's Reversal by paying {U}{U}, targeting the spell cast in step 1.
9. Swarm Intelligence and Storm-Kiln Artist trigger.
10. Resolve the Storm-Kiln Artist trigger, creating a Treasure artifact token.
11. Resolve the Swarm Intelligence trigger, copying Narset's Reversal, with the copy targeting the original Narset's Reversal.
12. Storm-Kiln Artist triggers, creating a Treasure artifact token.
13. Resolve the copy of Narset's Reversal, copying Narset's Reversal with the copy targeting the spell cast in step 1, and then returning the original Narset's Reversal to your hand.
14. Storm-Kiln Artist triggers, creating a Treasure artifact token.
15. Resolve the Narset's Reversal copy, copying the spell it is targeting and returning the original spell to your hand.
16. Storm-Kiln Artist triggers, creating a Treasure artifact token.
17. Resolve the copy of the spell.
18. Activate any number of Treasures by tapping and sacrificing them, adding enough mana to cast the additional instant or sorcery.
19. Repeat.
20. If the additional spell can be cast for less than four mana, this combo nets infinite mana, which may be used to repeat this combo targeting any other instant and/or sorcery card in your hand and/or on the stack.