Totentanz, Swarm Piper | Nim Deathmantle | Ashnod's Altar

Cards

Activate
Ashnod's Altar by sacrificing
Totentanz, adding ({C} magic symbol) ({C} magic symbol) .
When
Totentanz dies, it and
Nim Deathmantle triggers.
Resolve the
Totentanz trigger, creating a 1/1 Rat creature token.
Activate
Ashnod's Altar by sacrificing the Rat, adding ({C} magic symbol) ({C} magic symbol) .
Resolve the
Nim Deathmantle trigger from step 2, causing you to pay ({4} magic symbol) to return
Totentanz from your graveyard to the battlefield, and attach
Nim Deathmantle to it.
Repeat.