So it looks like they Book may have spoiled a major plot detail early.

So to get right to the point, I was fiddling around with the book when a stumbled upon the Flame Chasers Path section (see screenshots) and I noticed that specific Chrysos Heirs are placed on very specific Constellations.

You have Aglea on Mnestia, Tribea on Janus, and Castorice on Thanatos; obviously denoting which Chrysos Heir will or have inherited which Coreflame.

But what I also noticed is that Mydeimos is on Nikador which makes total sense except where we ended up in the story is Phainon being the one who is attempting to take up the divine seat of Strife.

Which leads me to believe that in the next patch we will have a story line where Phainon gets rejected by Nikador and is almost killed but we with Mydei will intervene. This will lead to Mydei finally taking responsibility and becoming the demigod of Strife which is just in time for his banner.

What is also interesting is that Phainon on the other hand is assigned to Kephale which also makes sense since he is being set up as like the Main Character for this arc. In which case I believe that he will be the last Chrysos Heir to get a Coreflame after much doubt about his own destiny and whether he really is a Chrysos Heir.

Bonus: I strongly believe that Cipher will be introduced next patch and will be the Chrysos Heir for Zagreus.