After reading your post about fixing Phi, I was wondering, what happened to Laphicet/Maotelus after Sorey went to sleep with him? I haven't bought Berseria yet (I'm waiting for a Steam sale lol), but since I already spoilered myself a bunch, I'm okay with spoilers.
Tales of Berseria (the game) doesn’t actually tell us, but from what I’ve heard, the Berseria novelization starts with the end of Zestiria, with Phi telling Sorey Berseria’s story. Which is a continuation (of sorts) of the Zestiria manga, where Phi tells Sorey he’ll “tell him a story of the past” in the final chapter before we cut to the epilogue with Epileo.
So I personally like to think that at least part of that time, Phi and Sorey were talking and swapping stories about themselves and the past, and given that Phi loves to explore, and Sorey loves history, I’d like to think they got along super well and by the time Sorey wakes up and rejoins the world, they’re really good friends and are on total first name basis with each other, haha. Just imagine, Sorey and Mikleo getting into a debate over something in a set of ruins and Sorey just tapping the ground and calling up Phi by name and being all, “Look, Maotelus, Mikleo and I are having a disagreement here about this thing, and I know it was around after you took over as the leader of the Five Lords, so can you settle this debate for us once and for all?” And Phi indulging him because, hey, he’s just chilling using the continent as his vessel and it’s not like the other Lords are all that talkative so he may as well.