If you don't use both, I'd say cthulhu scarf. You'll practically need it for the entirety of the playthrough.
My take on Brutal, Stained Calamity (SC's theme): Just like Raw, Unfiltered Calamity, it's a series of remixed leitmotivs, but instead of using DS/Crab/HM/Perf/SG/Cryoboi/BsE it uses...