Disclaimer

This should be taken with a lot of salt, since this is just a theory based on deductions and has not been confirmed as of yet and even i don’t fully believe it myself.

Theory

Duet night abyss’s prologue starts with the next era of this world. Where the creator built and created the ‘heaven’ trees which were created for an unknown purpose. It also guided life to adapt in the ways we see now.

Then during the years leading up to the story it guided the development of civilization to what we see now in game. During this time it may have created more back up plans or experiments; this lead is to be determined later.

Later before the game takes place it creates Bernica we don’t know why it did that but we know it had a reason to do it. During the time Bernica was being created she loaned out a subordinate body that being Bors to the empire. So they could help out with creating Berinca . During the time Berinca was created something went wrong and Vita sacrificed her left eye to keep Berinca alive. But in doing so she had to revert to a child like body and thankfully she had a person she trusted who saved their lives. After this Bernica and Vita grew up on Purgatorio island and then the story starts from here.

Other possibility

It created Vita’s body so it could be with Bernica, but due to something happening had to use the left eye of Vita’s body to save her. The rest being unknown after besides vita’s story.

Extra

Due to Vita transforming into a child like body she lost the mental strength to keep controlling Bors which ended up as Bors being set free fully.

Unknowns

- why does Vita not have any memories of before?

- why did this happen?

- what the true purpose of the heaven trees?

- what’s it original purpose for creating this world this way?

- why did one of alchemists save the both of them?

I did this theory post, because if i hadn’t my ear would have been talked off by the person how purposed this one.