Cauldron of Souls + Dross Scorpion + Arsenal Thresher + Grinding Station

Cauldron of Souls

Dross Scorpion

Arsenal Thresher

Grinding Station

How it works

1. Activate Cauldron of Souls by tapping it, giving Arsenal Thresher persist until end of turn.
2. Activate Grinding Station by tapping it and sacrificing Arsenal Thresher.
3. When Arsenal Thresher dies, its persist ability and Dross Scorpion trigger.
4. Resolve the Dross Scorpion trigger, untapping Cauldron of Souls.
5. Resolve the Arsenal Thresher trigger, returning it from your graveyard to the battlefield with a -1/-1 counter on it, and then choosing to reveal at least one artifact card from your hand to remove the -1/-1 counter.
6. When Arsenal Thresher enters the battlefield, Grinding Station triggers, untapping Grinding Station.
7. Resolve the Grinding Station ability from step 2, causing target player to mill three cards.
8. Repeat.

This clever loop relies on the interaction between Cauldron of Souls and Dross Scorpion to recycle your artifacts indefinitely. When you sacrifice Arsenal Thresher to Grinding Station, its new persist ability brings it back with a -1/-1 counter, but Arsenal Thresher's own entry ability lets you immediately counteract that drawback by revealing an artifact from your hand. Meanwhile, Dross Scorpion untaps your Cauldron of Souls upon the creature's death, and Grinding Station's own triggered ability untaps itself whenever Arsenal Thresher re-enters the battlefield. Repeating this sequence mills your opponent's entire library while generating an endless stream of sacrifice and entry triggers.