(*´ω`*)
-It would be very, very hard to fix things between Shuu and Reiji. They’ve been raised in such an awful environment for so long that their issues with each other are almost unfixable. Especially on Reiji’s end. The near entirety of Reiji’s trauma is shaped around Shuu and the way their mother treated them. Reiji’s hatred and jealousy of his brother is so deeply embedded that it’s debatable if he’d ever truly be able to get past them.
However, a decent parental figure would improve things at least a little bit. Shuu needs freedom and to be loved by someone who sees him as a child instead of a tool for getting ahead. Reiji needs attention and praise, to be treated like a person of his own instead of a servant and second-best to his brother. Love would go a long ways with both of them– even if neither of them would have any idea how to react to it. Letting both of them be children would be the best means of fixing anything between them.
Shuu would get past their previous years the best. If he hadn’t lost Edgar yet, it wouldn’t be too difficult for him to re-learn how to view his brother. If he had lost Edgar, though, there would be a whole new layer of trauma to wade through; one that he might not ever be able to truly leave behind.
Reiji, though, would have a difficult time moving on from how his mother treated the two of them. He’s been trained to see Shuu as the source of all of his problems, and getting him to think otherwise would be a challenge. He might not ever truly move past seeing Shuu as the competition that he can never overcome, but he would be able to relax a little and see Shuu more as family than a threat with the right parenting while he was still vulnerable.