Technomancer + Grinding Station + Auton Soldier

Technomancer

Grinding Station

Auton Soldier

How it works

1. Cast Technomancer by paying 5.
2. When Technomancer enters, it and Grinding Station trigger.
3. Resolve the Grinding Station trigger, untapping it.
4. Resolve the Technomancer trigger, causing you to mill three cards and return Auton Soldier from your graveyard to the battlefield as a copy of Technomancer.
5. When Auton Soldier enters, it and Grinding Station trigger.
6. Resolve the Grinding Station trigger, untapping it.
7. Holding priority, activate Grinding Station by tapping it and sacrificing Auton Soldier.
8. Resolve the Auton Soldier trigger, causing you to mill three cards and return Auton Soldier from your graveyard to the battlefield as a copy of Technomancer.
9. Repeat from step 5.

This crafty loop hinges on Technomancer and its recursive ability to pluck cheap artifact creatures straight from the graveyard when it enters the battlefield. By using Technomancer to resurrect Auton Soldier—which conveniently enters as another Technomancer copy thanks to its own copy effect—you generate an endless cycle of entering and leaving the battlefield. Grinding Station ties the whole operation together by exploiting this constant stream of arriving artifacts to continually untap itself, allowing you to sacrifice the looping Auton Soldier to mill your deck into oblivion.