I have very specific thoughts on Hajime post-game, in that I think both the tragedy and the beauty of his character and his arc lies in the fact he cannot undo what was done to him.
I don’t see Izuru and Hajime as separate people at all post-game, but I will use their different names to get my point across.
Hajime, Post-Game, is closer to Izuru than he is to Hajime. The simulation is limited; it can’t put his brain back together, it can’t fix what was purposefully broken. The boy that was Hajime can never exist the same way he once did. He’s been turned inside out.
It’s tragic, and it’s horrifying. He will always, to some degree, be cut off from the world, his own emotions, and be plagued by a profound sense of boredom, such is the burden of man-made divinity.
However, from that tragedy, Hajime’s final choice in the game is given even more meaning. He doesn’t know what the future holds, who he’ll be when he wakes up, but he pushes onwards anyway. And, after all that was done to him, he still chooses to live on by the name as Hajime Hinata. He chooses to be something more than the tool Hope’s Peak made from him.
I feel like that emphasis of choice is very important to Hajime’s ending. He isn’t Hajime because he and Izuru are seperate, or because the simulation overwrote Izuru, or somehow undid what was done to him. He’s Hajime because he wants to be.
He has all the talent in the world, and he is above the rest of humanity in so many regards, but he’d rather go by the name of the ordinary teenager he once was.
There’s something special about that to me.