Metalwork Colossus + The Ooze + Grinding Station + Arwen, Weaver of Hope

Metalwork Colossus

The Ooze

Grinding Station

Arwen, Weaver of Hope

How it works

1. Cast Metalwork Colossus by paying 0, which enters with at least two +1/+1 counters on it due to Arwen.
2. When Metalwork Colossus enters, Grinding Station triggers, untapping Grinding Station
3. Activate Grinding Station by tapping it and sacrificing Metalwork Colossus.
4. When Metalwork Colossus dies, The Ooze triggers, creating a Mutagen token for each +1/+1 counter Metalwork Colossus had.
5. When the Mutagens enter, Grinding Station triggers that many times, untapping Grinding Station
6. Resolve the Grinding Station ability from step 3.
7. Activate Metalwork Colossus by sacrificing two Mutagens, returning it from your graveyard to your hand.
8. Repeat.

This clever loop turns the massive mana value of Metalwork Colossus into a recursive engine, entirely fueled by casting it for free and turning its demise into profit. Arwen, Weaver of Hope ensures the Colossus enters with a fresh crop of +1/+1 counters, which in turn feeds The Ooze to spawn a surplus of Mutagen tokens every time the Colossus leaves the battlefield. Meanwhile, Grinding Station acts as the tireless mechanical heart of the operation, untapping with every single artifact entry and sacrifice so you can steadily mill away your opponents while feeding the cycle.