Board Thread:General BlazBlue discussion/@comment-7557996-20170109165019/@comment-30711988-20170110192611

It goes like this:
 * There was a PFD named "Saya". She was first to become a Successor, so she is the Origin (I'll call her "the Origin"). After humans dumped her into the Boundary, she returned to Master Unit, and became an "Amaterasu".
 * There was a 5th PFD (I'll call her "Five"), which was a huge irregularity, and a perfect copy of some girl that was "devoured" by her brother. Jubei killed Five.
 * Saya that is Ragna's little sister (I'll call her "Saya") was modelled after Five, and was used as a basis of Lambda, Mu and Nu.
 * Lambda, Mu, Nu, Saya and the Origin were made with parts of the same soul.
 * On December 25, 2194, the Origin used the power of Takemikazuchi's blast to recreate herself in Mu, so Mu got another part of that soul and later became Noel.
 * Saya then became Izanami's vessel. Izanami is the Origin's Drive, and the opposite of her power to create, which is called "Izanagi System".
 * Noel is the Origin reborn, so she kinda sorta was a one person that existed in two places at the same time. That is why, despite not knowing about all those godly matters, Noel separated herself from Mu in CF.
 * Mu still got a part of that one soul. However, both Lambda and Nu evolved, becoming their own selves instead of being the Origin's copies, and their souls have changed.
 * Noel merged back with Mu, and then, as the Origin, absorbed Izanami, her Drive. But since Lambda and Nu's souls evolved, Noel was unable to merge with them.
 * Noel then absorbed the Origin's body that was in the Master Unit, and that's it for her.
 * Ragna noticed that Kushinada's Lynchpin was modelled after the Master Unit, which means that the Unit should also have a soul inside of it. That is the Origin's soul that was left there because Noel absorbed only the body. Ragna then left his world to be with the Origin in the Boundary.

So, Noel just absorbed Izanami (Saya's body), and the Origin's body, but she does not have all parts of their soul. Now she's essentially Saya that is Ragna's little sister. And the Origin is chilling in the Boundary with her "brother".

What we don't know, is why Terumi Saya and Tenjo look the same, like Izanami-controlled Saya.