Myr Retriever + Workshop Assistant + Grinding Station + Mycosynth Golem

Myr Retriever

Workshop Assistant

Grinding Station

Mycosynth Golem

How it works

1. Activate Grinding Station by tapping it and sacrificing Workshop Assistant.
2. When Workshop Assistant dies, it triggers, returning Myr Retriever from your graveyard to your hand.
3. Resolve the Grinding Station ability, causing target player to mill three cards.
4. Cast Myr Retriever by paying 0.
5. When Myr Retriever enters the battlefield, Grinding Station triggers, untapping Grinding Station.
6. Activate Grinding Station by tapping it and sacrificing Myr Retriever.
7. When Myr Retriever dies, it triggers, returning Workshop Assistant from your graveyard to your hand.
8. Resolve the Grinding Station ability, causing target player to mill three cards.
9. Cast Workshop Assistant by paying 0.
10. When Workshop Assistant enters the battlefield, Grinding Station triggers, untapping Grinding Station.
11. Repeat.