Cast Approach of the Second Sun by paying {6}{W}.
Holding priority, cast Unsubstantiate by paying {1}{U}, returning Approach of the Second Sun to your hand.
Cast Approach of the Second Sun by paying {6}{W}, causing you to win the game.

Win the game

Approach of the Second Sun

Unsubstantiate

Cast any instant or sorcery by paying its mana cost.
Holding priority, cast Unsubstantiate by paying {1}{U}, targeting that spell.
Thousand-Year Storm and Storm-Kiln Artist trigger.
Resolve the Storm-Kiln Artist trigger, creating a Treasure token.
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.
Storm-Kiln Artist triggers for each copy made this way, creating that many Treasure tokens.
Resolve the first copy of Unsubstantiate, returning the original Unsubstantiate to your hand.
All remaining Unsubstantiate copies fizzle due to no longer having a legal target.
Holding priority, activate the Treasures by tapping and sacrificing them, adding {1}{U}.
Repeat from step 2.

Infinite colored mana

Infinitely powerful Storm-Kiln Artist

Infinite magecraft triggers

Infinite storm count

Infinite Treasure tokens

Thousand-Year Storm

Storm-Kiln Artist

Cast any card by paying its mana cost, or wait for an opponent to cast one.
Holding priority, cast Unsubstantiate by paying {1}{U}, targeting that spell.
Swarm Intelligence and Storm-Kiln Artist trigger.
Resolve the Storm-Kiln Artist trigger, creating a Treasure token.
Resolve the Swarm Intelligence trigger, copying Unsubstantiate, with the copy targeting the original Unsubstantiate.
Storm-Kiln Artist triggers, creating a Treasure token.
Resolve the copy of Unsubstantiate, returning the original Unsubstantiate to your hand.
Holding priority, activate the Treasures by tapping and sacrificing them, adding {1}{U}.
Repeat from step 2.

Swarm Intelligence

Cast Unsubstantiate by paying {1}{U}, targeting Dualcaster Mage.
Orvar, and Storm-Kiln Artist trigger.
Resolve the Orvar trigger, creating a token copy of Dualcaster Mage.
The Dualcaster Mage token enters the battlefield, copying Unsubstantiate, targeting the original Unsubstantiate.
Storm-Kiln Artist triggers, creating a Treasure token.
Resolve the copy of Unsubstantiate, returning the original Unsubstantiate to your hand.
Resolve the Storm-Kiln Artist trigger from step 2, creating a Treasure token.
Activate both Treasure tokens by tapping and sacrificing them, adding {U}{U}.
Repeat.

Infinite creature tokens

Infinite ETB

Orvar, the All-Form

Dualcaster Mage

Cast Karn's Temporal Sundering by paying {4}{U}{U}.
The Sixth Doctor triggers, copying Karn's Temporal Sundering.
Resolve the copy of Karn's Temporal Sundering, causing you to take an extra turn after this one.
Holding priority, activate Isochron Scepter by paying {2} and tapping it, casting a copy of Unsubstantiate without paying its mana cost.
Resolve Unsubstantiate, returning the original Karn's Temporal Sundering to your hand.
Repeat each turn.

Infinite turns

The Sixth Doctor

Karn's Temporal Sundering

Isochron Scepter

Cast Sea Gate Stormcaller by paying {1}{U}.
Sea Gate Stormcaller enters the battlefield, copying the next instant or sorcery spell you cast with mana value two or less.
Cast Unsubstantiate by paying {1}{U}, targeting Sea Gate Stormcaller.
Sea Gate Stormcaller, Orvar, and Storm-Kiln Artist trigger.
Resolve the Sea Gate Stormcaller trigger, copying Unsubstantiate, targeting the original Unsubstantiate.
Storm-Kiln Artist triggers, creating a Treasure token.
Resolve the copy of Unsubstantiate, returning the original Unsubstantiate to your hand.
Resolve the Orvar trigger, creating a token copy of Sea Gate Stormcaller.
The Sea Gate Stormcaller token enters the battlefield, copying the next instant or sorcery spell you cast with mana value two or less.
Resolve the Storm-Kiln Artist trigger from step 4, creating a Treasure token.
Activate both Treasure tokens by tapping and sacrificing them, adding {U}{U}.
Repeat from step 3.

Sea Gate Stormcaller

Cast Unsubstantiate by paying its mana cost.
Holding priority, cast Dualcaster Mage without paying its mana cost due to Aluren.
When Dualcaster Mage enters, it triggers, copying Unsubstantiate, targeting Dualcaster Mage.
Resolve the Unsubstantiate copy, returning Dualcaster Mage from the battlefield to your hand.
Repeat from step 2.

Combos with "Unsubstantiate"