I dunno. If you like the villain on that basis, by all means, go for it. I don't want to make anyone dislike the game, and I respect your opinion.
Personally, though, I felt like the game almost explored ideas like mental illness and evil and stuff, but it stopped short of really saying anything meaningful about it, which left the villain feeling more like a Saturday morning cartoon villain to me.
I also just really disliked that the killer was someone who wasn't really brought up until very late in the game (I believe he was only hinted at very late in one route and formally introduced with Hitomi's somnium) by a concept that was similarly withheld from the player until really late in the game. I was theorizing on the killer all game long just using the suspects in the game, and it felt like the game was like "lol but there was a mind jumping body swapper in the mix the whole time, and btw, So's son was a psychopath! Who could the killer be?! :O" It wasn't a super satisfying reveal to me because it felt sort of cheap, because critical information is held back until super late. I just wasn't really huge on how the endgame played out with all of that. It felt like theorizing was pretty pointless since you don't find out about critical information that you need until very late, at which point the game becomes very obvious and the last few hours are a lot of plot dumping about stuff that's easy to piece together.
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