Rasputin Dreamweaver + Nim Deathmantle + Altar of Dementia

Rasputin Dreamweaver

Nim Deathmantle

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Rasputin Dreamweaver.
2. Nim Deathmantle triggers, causing you to pay 4 to return Rasputin Dreamweaver from your graveyard to the battlefield and attach Nim Deathmantle to it.
3. Resolve Altar of Dementia's ability, milling target player a number of cards equal to Rasputin Dreamweaver's power.
4. Activate Rasputin Dreamweaver's first activated ability seven times, adding seven C.
5. Repeat any number of times.
6. Once you have infinite colorless mana, you may repeat this loop with any other creatures you control, effectively blinking them through sacrifice and reanimation.