Nim Deathmantle triggers, causing you to pay ({4} magic symbol) to return Rasputin Dreamweaver from your graveyard to the battlefield and attach Nim Deathmantle to it.
Activate Rasputin Dreamweaver's first activated ability seven times by removing seven dream counters from it, adding seven ({C} magic symbol) .
Repeat any number of times.
Once you have infinite mana, you may repeat this loop with any other creatures you control, effectively blinking them through sacrifice and reanimation.