Cast Essence Flux by paying , targeting Eternal Witness
Storm-Kiln Artist triggers, creating a Treasure artifact token.
Resolve Essence Flux, blinking Eternal Witness
When Eternal Witness enters the battlefield, it triggers, returning Essence Flux to your hand from your graveyard.
Activate the Treasure by tapping and sacrificing it, adding .
Repeat.
This loop is a masterclass in recursive recycling, turning a simple two-mana spell into a self-sustaining engine. By casting Essence Flux to blink Eternal Witness, you ensure that the spell you just cast immediately returns to your hand from the graveyard, ready to be played again. Meanwhile, Storm-Kiln Artist acts as the engine's financial backer; its magecraft ability churns out a Treasure token with every cast, which you can easily sacrifice to pay the exact blue mana needed for the next iteration of Essence Flux.