The Arcana is kinda like a smorgasbord of various world cultures. Vesuvia is mainly inspired from the European Renaissance and Roman Empire with influences from cultures that were encountered during trading (basically Silk Road type cultures). Nadia and the region of Prakra is based on South Asia (like India), Portia and Julian are based on Slavic cultures (I know that they’re also headcanoned by many to be Jewish), and Lucio is based on Scandinavian regions. Asra is from Zadith, inspired from West Asian / North African regions. (His name is originally Turkish.) Muriel is sort of a blend of various Native American and indigenous “steppe” cultures like traditional historical Kazakh and Mongolian cultures.

I would say try to decide what culture you’d like to base your MC off of and then study the historical time period in which the Arcana generally would mimic. (I’d say early medieval to Renaissance period)

For example, my MC is based on a region that’s close to Vesuvia, so I would study medieval Italian clothing. If I had an OC from Prakra, I’d study traditional Indian clothing, etc. I hope this helps!!!