Retconning Daenism, the Bidar, and Geraja

[Wu Han]

[...] Overall I do favour Option A for terminology that is very entrenched, like the name of the religion itself and its founder, while we can use option B for everything else. [...] We could maybe rename the religion as Dhyanism, or keep Daenism and claim it as a “corruption” of the original Sanskrit, or take Wu’s suggestion to have it originate from दैन्य. [...]

I agree that it's preferable to maintain the old terms rather than create new ones, given their longstanding existence in the game. I think the religion could be something like "Daena-dharma" (meaning something like "Doctrine of insight into suffering") in the original Sanskrit, with "Daenism" being the English/Luthorian version, taken from the "Daena" root. This is similar to Buddha-dharma → Buddhism. Alternatively...

One additional point, it may not even be necessary to change much of the terminology if we consider that the first contacts of the western world (Artania and Majatra) with Daenism was via Aldegar. Maybe Daena and Bīdār was how people in Aldegar called things that had a different name in the original languages of Daenism.

I think this could work, though I also think it is somewhat unnecessarily complicated, given my first point here. However, this point makes me think that it might be interesting to have a Daenist off-shoot in Aldegar that continues your original fusion with Zoroastrian/Manichean philosophy?