I kind of wonder given the inheritance from old DND being morphed into a new context if the demons aren’t basically the distilled idea of racial prejudice somewhat separated from a specific race being targeted. Among Japanese people I suppose I once read the work of a fascist who portrayed Koreans quite like the Demons (the manga Shamo, which needless to say I don’t recommend), but I think that that was probably a significant outlier in terms of the style of anti-Korean racism.