I'm on the side of Ash staying but if he's not, Nemona is clearly the best choice for next main character. They have the same energy and they could easily pass it off as her journey that she had before the game starts.
Nemona is my fav pick for the companion alongside Arven and Penny, but if she's the MC I'd be very happy
Honestly this time the game has handpicked the companions for Ash honestly. Nemona, Arven, Penny and Ash would be the perfect quartet
I'm okay if Goh and Chloe continue as long as those are relevant
Would be heavily disappointed if we get gym leaders instead of those 4, same with new OCs
I just hope they still get consistent focus even if they aren't in the main cast