The problem is, having an inferiority complex as the reason to commit numerous atrocities and be a dick to your friends is never a good explanation for why someone tuned evil. It makes you go from feeling sorry for someone to making you hate them.
Both J and Shania do this and both are handed poorly. In Joran' case it also doesn't make sense that he would turn from a legitimately nice kid into a heartless monster as soon as he became mobius.
In both cases the redemption is also poor and makes everything worse. Both are turned into idiots who couldnn't realize something obvious despite pretty much everyone telling them multiple times (which also applies to N now that I think about it.)
Sena also had an inferiority complex, but she didn't turn into a mass murderer
Nah, I feel your reading of him is way too uncharitable, and I say that as someone who thought the bad guys were very disappointing in this game.
No reason is a good reason to commit mass murder. Does anyone really think N or Jin were more justified in killing people because a cute girl was involved? His reason starting from an inferiority complex is a good base as any for an antagonist.
You are forgetting his transformation from sweet kid putting a strong front into J involves gaining the knowledge the he's always been a bullied fat loser getting comically run over by levnises or whatever in every single lifetime, also that people don't really die and are just reborn to keep fighting the pointless war. Harder to keep holding onto hope after that when he already wasn't in the strongest position in the first place.
Your point that they were idiots who just couldn't realize something obvious feels wildly off the mark, like asking why someone in deep depression hasn't just tried being happy. The game gets so, so preachy with this shit in the last chapter that it is hard to miss the point being made.
"Why do you insist on punishing yourself like this?"
"You took the wrong path, and then you had to walk it alone"
"Regret owns you"
"If only I'd made the right choice"
"If what happened, hadn't"
"Clinging to the past, obsessively"
"What you've become is regret itself"
"You could try to move forwards again" "After so long?"
"Regret is our be all and end all"
"Blindly we never tried to change ourselves, wishing only that the world would instead"
All of these are said in the context of N but it's clear it applies on some level to all Moebius (at least the ones that have actual characters) based on how moebius' true nature is described. There's a reason why N, Joran and Shania are the characters most prominently displayed when confronting Z at the end. There's also a reason why J and Shania's powers as Moebius are warped reflections of what they actually loved but couldn't do either because the world fucked him over (Joran) or because she made the wrong choice (Shania). People so consumed by regret, people so convinced that "welp, it's already fucked, no point to it, no choices left, unfixable, no hope for me" that they have bogged themselves down into a personal hell of their own creation and are now too afraid to escape because of all the time, effort and actions wasted into self-torturing delusions. Notice how Aionios itself is self-made hell, and the moebius fight to protect it.
N, J and Shania do an at least adequate job of representing all of this, I feel (compared to the other 20 something assholes)
I would exclude Z since he would say anything if it meant keeping his world intact as we see when he warns Noah that freeing the worlds from his control would lead to destruction. What other characters bring it up though?
In the flashback from 1000 years ago where Crys and M create the homecoming ceremony the consul that was about to execute the soldier remarks the same thing. Homecomers don't reincarnate in this system.
