Rasputin Dreamweaver + Cogwork Assembler + Mycosynth Lattice

Rasputin Dreamweaver

Cogwork Assembler

Mycosynth Lattice

How it works

1. Activate Cogwork Assembler by paying 7, creating a token copy of Rasputin Dreamweaver with haste.
2. Put the oldest Rasputin Dreamweaver into your graveyard due to the legend rule.
3. Activate Rasputin Dreamweaver's first ability seven times by removing seven dream counters from it, adding 7.
4. Repeat.

Mycosynth Lattice is the grand catalyst here, turning all permanents on the battlefield into artifacts so that Cogwork Assembler can finally target creatures like Rasputin Dreamweaver. Once the stage is set, you activate Cogwork Assembler to churn out a hasty copy of Rasputin Dreamweaver, leveraging the legend rule to send the original to the graveyard while keeping the fresh clone around. Because the new Rasputin Dreamweaver enters with all seven of its dream counters intact, you can immediately strip them away for a swift return of seven colorless mana, fueling the next activation of Cogwork Assembler to repeat the loop endlessly.