Blasting Station + Dualcaster Mage + Extract from Darkness

Blasting Station

Dualcaster Mage

Extract from Darkness

How it works

1. Cast Extract from Darkness by paying its mana cost
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it and Blasting Station trigger, with Dualcaster Mage targeting Extract from Darkness.
4. Resolve the Blasting Station trigger, untapping it.
5. Holding priority, activate Blasting Station by tapping it and sacrificing Dualcaster Mage.
6. Resolve the Dualcaster Mage trigger, copying Extract from Darkness
7. Resolve the Extract from Darkness copy, causing each player to mill two cards and returning Dualcaster Mage from your graveyard to the battlefield.
8. Repeat from step 3.

This looping setup relies on casting Extract from Darkness to fuel the graveyard, but the true engine comes alive once Dualcaster Mage enters the battlefield to copy that spell indefinitely. Because Dualcaster Mage constantly returns itself from the graveyard directly to the battlefield through the resolution of the copied spell, you can sacrifice it to Blasting Station for a steady stream of damage while Blasting Station's own untap ability resets the artifact for the next iteration.