I'm not sure who's the ML you're referring to... but here goes. Irene (mc) holds the soul of the goddess of balance (Erin). So, she is not necessarily her reincarnation, but Irene is more of a vessel. The demon god and heavenly god worked together to reincarnate A PIECE of Erin's soul (now Irene) back into their world, so that she would used to resurrect their lost sibling --- Erin.
Ren, the pixie, and the dragons from the first chapters were all followers/close companions of Erin when she was first revived as a human mage of the middle land. This was BEFORE the demon god and heavenly god reincarnated her for a SECOND time in their world as Irene (mc).
So the demon lord and heavenly lord also orchestrated the encounter behind Karaban and Sein (Irene/MC's parents) so that they will give birth to a baby with both dark and divine powers.
((Sorry for the long comment I hope I helped explain it... if you have confusions or questions I will try my best to answer ))
Thank you so much...i was so confused with all these. Made my day(づ￣ ³￣)づ
No problem!! I'm glad I was able to help (●'◡'●)
Somebody please explain it to be what os going on with Erin and the ml.! What is her connection with all of them...