Requires

Thousand-Year Storm must be on the battlefield. Storm-Kiln Artist must be on the battlefield. Unsubstantiate must be in hand. You have at least one other instant or sorcery card in hand. Mana needed: plus enough mana to cast the other instant or sorcery

Steps

1. Cast any instant or sorcery by paying its mana cost.
2. Holding priority, cast Unsubstantiate by paying , targeting that spell.
3. Thousand-Year Storm and Storm-Kiln Artist trigger.
4. Resolve the Storm-Kiln Artist trigger, creating a Treasure token.
5. Resolve the Thousand-Year Storm trigger, copying Unsubstantiate once for each instant or sorcery you've cast before it this turn, with each copy targeting the original Unsubstantiate.
6. Storm-Kiln Artist triggers for each copy made this way, creating that many Treasure tokens.
7. Resolve the first copy of Unsubstantiate, returning the original Unsubstantiate to your hand.
8. All remaining Unsubstantiate copies fizzle due to no longer having a legal target.
9. Holding priority, activate the Treasures by tapping and sacrificing them, adding .
10. Repeat from step 2.

Results