Plus this keeps me from having to (at least in my own mind) figure out how a species from a /different world/ could look so identical /and/ interbreed with no adjustments needed, because at that point we’re kind of looking at mimetic energy beings and I don’t think I have the strength for that.

And the Regent always mentions that they have few light resources, in particular, so a) there are some and b) it looms fairly large in /his/ mind at least. Plus, if Dixing needs light to survive down there, and have lost their prior generation technology, it totally explains why Haixing would have /let/ them have the Hallows right after a huge conflict in which a Dixing faction was the aggressor.