i really dislike ouma, but the thing that really pisses me off is when people compare him to one of the following three characters: byakuya togami, nagito komaeda, and fuyuhiko kuzuryuu.
1. togami has very well explained reasons why he behaves the way he does. he was taught from birth that the world is a cutthroat business transaction and that if he doesn't rise to the top, he will die in the gutter. he acts the way he does in the killing game because that's literally all he knows. his life has always been a killing game, just with less directly lethal consequences. seeing sakura sacrifice her life for her friends directly contradicts the world that togami has been living in, and when he realizes that the world is not as dog eat dog as he was conditioned to believe, he changes. ouma seems to already know that the world is more compassionate than he'd believe, he just doesn't care. he actively seeks to try and make others feel threatened and upset, because he wants to. he doesn't give a shit if the people around him are good or not; he just wants to cause as much chaos and hatred in his wake as he can. and i feel like the reveal at the end of the game where ouma was actually a "good guy" is another way to excuse his actions in the game. togami meanwhile has believable and sympathetic reasons to be the way he is.
2. komaeda also has well explained reasons why he acts the way he does. while unfortunately a lot of his motives do stem from mental and physical illnesses, the effects are actually somewhat realistic. komaeda's been so used to living in extremes that it makes sense for him to see the world that way. his talent has also conditioned him to expect extreme good to come out of extremely bad situations, and vice versa. his ideal of hope is related to this, and he craves it so desperately that he will act in unpredictable and backwards ways to see it. ouma doesn't seem to be looking for the best in people; he already sees the good in a lot of his classmates. komaeda finds out that his classmates are terrible people, and thinks he's doing a good thing by ridding the world of them. ouma, meanwhile, gets rid of gonta, miu, and kaito directly, three people that are doing very big, net good things: gonta is by far the kindest and most trusting of the cast, miu is an inventor looking to improve humanity and its output, and kaito is the most confident and courageous person in the cast who was willing to take a literal poison arrow for ouma. and yet, ouma still actively decides to kill them for seemingly no reason other than to save his own ass.
3. fuyuhiko grew up in a (quite literally) cutthroat world, and despite his innermost self being a loyal, genuine, and devoted person, he had to hide those parts of himself in order to survive every day. that constant pushing down of his emotions gave him a hard, disinterested exterior. it could be argued that this was actually fuyuhiko's way of being kind to others, by trying to keep them away from his life of crime and violence. fuyuhiko is aware of the selfless nature of people, with peko laying down her life constantly to protect him, his sister being devoted to him to the point of near idolization, and even ibuki celebrating his recovery with a concert. when his outer layers start to deteriorate, he's scared. he knows that he's been a bad person, and his entire character arc is his atonement for the destruction that happened around him. ouma sacrifices people around him willingly, does not atone for any of that destruction, and is eventually vindicated for seemingly no goddamn good reason. ouma is treated as a "good guy deep down" despite him showing absolutely no signs to validate this idea. fuyuhiko and ouma may share a voice actor, but they do not share anything else in terms of characterization.
