In the Ancient times people didn't have flags but rather groups who were spiritual made their own banners and came together in a unison with all sorts of symbols in the fray. Of course that doesn't apply completely today but we should take the same philosophy in coming up with any new group conceptions. The Gods don't have flags- they do have their own individual sigils and covens for example. The internet also exists and it already seems to be destroying national differences in the races, so any flag conceived here would have to be reflective of all Aryan culture and not just the Germanic one.
I had a design actually, but I think I'm gonna make it into something else one day instead of posting it here lol. The JoS Satanic element in your flag is lacking though I must say. It needs to be more striking, maybe adding inverted stars for example or the Algiz rune.