Edwin is definitely an extremely fascinating MC. He seems very dissasociated, almost to the point of being emotionless. We occasionally see flashes of his true self, and it's a very chaotic mixture of a savior complex, mommy issues, unresolved anger, and willful ignorance of his true nature, because he knows deep down what's inside the rabbit hole of his sexuality. He does a lot of compartmentalizing to cope with his fucked up circumstances, as any other explanation would mess him up even more.
Let's start with his relationship with our favorite pornstar, Vicky. Our MCs problems truly began the first time 15 year old Edwin saw his mom getting gangbanged on the screen. Now, Edwin was already a nasty kid with a chip on his shoulder, raised by a single mom who couldn't possibly control him, but all kids eventually mellow out of their rebellious phase, just like Edein seemingly calmed down and became a fine young man. But we also know that there's a huge darkness lurking beyond the "mediocre nerd" surface Edwin presents.
He just seems like he's always pretending in social settings, almost none of his interactions at the start seem genuine. He gets better as the game progresses, but his lack of socialization is clear when the game starts. He's basically a shut in loser who watches his mom getting glazed by strangers in his free time, and his only "friend" is Ian, who has his own set of issues and complexes regarding Edwin and Vicky that deserve an analysis of it's own. My point is, Edwin is a fucking weirdo with a mother complex that hasn't even began to unpack his issues, because instictually, he himself is aware what lurks underneath the surface.
It's also very telling that Kat, the Dommy GILF herself, has immidiately indentified Edwin as her possible protege in sadism. Sure, Ian has been there for longer, but Ian still has that childlile naiveté to himself that makes him unsuitable for Kat's brand of sadism and torture. Plus, Kat smelled blood as soon as she found out about Vicky's past in porn, and how it affected Edwin. The biggest weapon Kat has in manipulating Edwin is Rosalind, who stirs up his mommy issues and draws the biggest parallel with Vicky, as they're both single mothers scratching out a living for their kids on their backs. We also see most of Vicky's flashbacks during Rose scenes, which further confirms my theory.
Edwins whole identity is based around repaying his mother for "enduring" humilliation for his sake, and his borderline obsession with Vicky suggests a lot of unresolved and unadressed issues, which resulted in Edwin's sadistic sexual tendencies. His compartmentalization of his mother's dark sexuality and her wholesome housewife persona means that he never truly came to terms with his mom's porn career, and now whenever he sees a woman enjoying degrading and humilliating sex, he assumes that she's "laying back and thinking of England", just like his mother must have done, because good women supposedly aren't supposed to enjoy degrading and humilliating sex, and that creates the dichtomy of his mother being a saint and a whore in his head. Edwin has a much more complete picture of Victoria than Ian, but I think that not even Edwin has the complete image of Victoria.
For example, during the sex scene at Rose's house, after he finds out Rose enjoys demeaning dirty talk, we get a flashback to Vicky enjoying a gangbang and going completely crazy, which Edwin copes with by choosing to believe that Rose's simply playing it up for Edwin just like Vicky did for the cameras.
The same thing happens during Rose's porno shoot, after Rose gets completely lost in lust, we get a flashback of Vicky having some playful banter with a pornstar, and then later getting fucked silly by him, Edwin once again compartmentalizes this by assuming the girls were taking back control by forcing themselves to enjoy degrading sex.
There's also Felicia's photoshoot, where Edwin has the option of getting angry at Felicia's flippant attitude towards the competition, and spitting on everything his mother suffered through, and we get another flashback of Victoria lying to little Edwin about working at the bar, and then a few hours later we see Vicky completely unconcious, getting completely glazed by a few strangers.
This shows us Edwin's deep seated anger, that even Edwin himself doesn't know where it's coming from, as is evident by his inner monologue at the time.
There's also an interesting tidbit during Edwin's pillow talk with Mina, where he admits that the concept of defiling and corrupting something pure turns him on, and we get another flashback of Vicky getting fucked and verbally humilliated by some thug looking pornstar.
There are a few more examples of Vicky's porn career affecting Edwin's sexuality, but I can't be bothered to find them all. My point is that Edwin needs to come to terms with Vicky's porn career and sexuality if he wants to have a shot at a healthy sexual life. His compartmentalization and repression of his anger only serves in Kat's favor, making her manipulation of Edwin easier, as Edwin still hasn't come to terms with Vicky's role in his sexual formation. We've sees the full gravity of his choices hit him when he realizes that August might have been one of his mom's producers and/or pimps, and he's so relieved by Vicky's denial that he doesn't notice that she's obviously lying, and the very next day she prods Ian for information about August, but he wisely doesn't let anything slip.
Vicky's been getting more and more nosy about Edwin's line of work, and I'm afraid that the resolution of that won't be pretty, but it will be pivotal for Edwin's character. I do think that Edwin's a bit of an unreliable narrator, as he's probably hiding some things from the player, but I think we have a clear enough picture of him to make an accurate assesment. Of course, YMMV depending on your playthrough.
Anyway, thanks for reading this wall of text. Of cours, I may be completely wrong, but theorizing is the part of the charm until we get the full picture.