Please do take this with a grain of salt and add anything you think should be added or changed to this. Also sorry for the wording my brain is just a little tired right now so sorry again.

Theory

Charons and sols are of them same species but are not the same species individually. This can be seen in how they are born.

Charons are born because of certain genes from the ancestors of both peoples taking effect and becoming dominant. Thus the change in blood line and the development of charon marks on their body. And for more pure individuals come more power but more backlash and inturn.

Sols still have these blood lines as well but it has become diluted leading to them being spared from what charons deal with but also in-turn not having the capacity for magic.

Of course we don’t know which is more dominant but we can guess. My guess being charons.

Also on this the sols are oddly similar to modern humanity and we are a good example of what will happen in the future of duet night abyss’s world. That being the lost of other races and the dilution of bloodlines with in us. Eventually leading to a loss of physical power and heightened mental power. Both being seen in the sols already in game.

Also on possible ancestor blood lines only one so far that is certain and that being beast men.