One thing not mentioned much is when Elidibus is losing it right before he transforms we get spoken to from "A voice from within" which is voiced by Ardbert and is responding directly to what Elidibus just said, to me this reads as either:
A: Ardbert hangs about but out of respect just keeps to himself unless he feels the need to say something.
B: He's mostly dormant inside of us but on some level is aware of what going on and certain things rouse him.
I like to believe it's A, I like the idea that as a reward for all he went through he, like Graha get's to come with us on our next adventures while not physically he'll be able to experience them as himself through us, it also gives another voice to us, which they like to use like with the Twins as given we don't have one of our own, it gives them something up until this point we as a character have lacked, some semblance of "inner thoughts"
I know some people dislike stuff like this, I personally love it, but I think we all need to remember that while we've a greater degree of customisation on our character we are still taking control of a set character, we can chose their race, gender and appearance but we are all still playing "The" Warrior of Light/Darkness.
A lot of complaints from ARR that even the devs still make jokes about was we were more the Warrior of Nodding and Fist punching over being a real character in the story, people called for us to do more, act more even have an actual voice over, but as this is a set story for every bit of that we gain it means we become more set in stone, we've gained some choice over what we say but more in a "You're going to say/do this anyway, but were you scarastic, sad, angry, happy e.c.t" sense.
You can rename Cloud in 7 or Tidus in 10, but no matter what we chose to call them, Cloud is still Cloud and will act the same, Tidus is still Tidus and no matter how we customise them, we're still the WoL/D.
Our character has come a long way since ARR and they've gotten pretty creative with making us feel more alive, while some like myself love that unfortunately you can't please everyone and for every bit of established character the WoL/D gains, the space for headcanon shrinks.