Cross steampunk with the sort of masks you might imagine worn by wild riders out in the post-apocalyptic world of Mad Max. If you can then you might end up with something like the “The Sheerwood Bandit” from OcultoMasks on Etsy.
Mask 12 means only one thing in the 12 Masks of Halloween countdown. Tomorrow is Halloween! Just keep in mind that a wizard may transform you into whatever costume you wear.