I DO NOT agree with characters in books marrying each other, but for the purposes of this story I can't avoid it. The reasoning behind this is that with the ancient Greek gods marrying a sibling, aunt, niece or what we today classify as a relative didn't apply to them. I'm not too sure why they were exempt from this but they were. Also if I've marked something in Italic print then it's an actual name, realm, place, person, or something else that is historically accurate. Also what each god or goddess is known for will be in Italic too. Basically if it is in Italic then there are records of it somewhere in history, so the info is courtesy of history being made!
If it's a normal print then chances are high it is 100% made up from some corner of my mind. What corner in my mind exactly I haven't a clue, sometimes it's a roller coaster in there, lol! If you need to know how something is possible then you should probably leave now, there are parts of this story that can't be explained. They are the way they are just because, so magic! That's how my brain has computed this issue, if you find this unagreeable I'm very sorry but this is just how my brain has computed it (I hold the pen here).
Even though in Greek history some of these Primordial Deities don't actually have a physical body, Chaos starts out like it is accurate for Greek history only to form a body after her siblings come along.