
I saw people talking about Rei or Kazuha but I figured it was obvious that at some point his personalities would come together. Idk I feel like hes reached a point where he doesn't need each aspect of himself separated from the others as a way to cope with certain problems hes had. Hes reached a point where he can accept all parts of him and all that has happened up til now, it's like he was a scattered puzzle and now with his cuties help it's all coming together. Once it does there's not gonna be any separate parts of him, it's just going to be him. Regardless of them all having different names and such all of them are a part of him and always have been and always will be so it cant just be Rei or Kazuha. At least that's how I see it, I am curious about what name he's gonna take on or if he'll even take on a new one

I feel similar to you. I think some of the alters were always closely related to Yuma, and having a close relationship with him years from their birth has help overcome some of the cracks on Kasuha's mind.
I think there are three main questions still on the air.
1- What triggered Rei's birth
2- Who is the "mature" alter, the one Yuma only watched from afar
3- If Rei and Kasuha will come to terms to stay both with Yuma, or one of them will disappear. (The translators did suggest that the ending won't be so clinically accurate)
That's it? Aight then