Woe Strider + Dualcaster Mage + Extract from Darkness

Woe Strider

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 triggers, targeting Extract from Darkness.
4. Holding priority, activate Woe Strider by sacrificing Dualcaster Mage.
5. Resolve the Dualcaster Mage trigger, copying Extract from Darkness
6. Resolve the Extract from Darkness copy, causing each player to mill two cards and returning Dualcaster Mage from your graveyard to the battlefield.
7. Repeat from step 3.

This loop cleverly exploits Dualcaster Mage's enter-the-battlefield trigger by copying the very spell that returns it to the battlefield, Extract from Darkness. Woe Strider serves as the essential sacrifice outlet to bin the Mage and restart the chain, while its passive scry ability turns the endless repetition into a way to filter your entire library. As an added bonus, the repeated resolution of Extract from Darkness mills every opponent out of the game while generating an unbounded storm of triggers.