Oh, but I DID find that Dorian paralleled aspects of Sunny's personality and thematic relevance very much! It was just as though they had taken a darker turn in Dorian. Both Sunny and Dorian are presented as characters who are impressionable followers, which is also the core trait that leads to their downfall and "corruption." They're both insatiably curious when it comes to ideas of the world and of men, wanting to pick apart how things work at the seams, and wrap their thoughts about it in some digestible way. They're both obsessed with the idea of self preservation of purity, in one way or another. Dorian feels sick in seeing that his decaying portrait reflects his lacking moral state in physical form (and the family portrait that has the faces scribbled over + Sunny's distorted face in the mirror in the painting-covered Red room? Absolutely sick parallels). Sunny is stuck inside his relentless mental looping, his idea that he is disgusting, unforgivable, and sick being what stops him from changing his destructive ways (and did I mention they're both self-destructive?).
Narratively, both of their journeys culminate in a spontaneous episode of bearing their heart open to an emotionally wounded Basil. While Dorian reacts defensively, and we don't know how Sunny reacts, the result is that they both lash out at him in a rash frenzy. And oh my god, they're also both SUCH romantics, for better or for worse?? The way Dorian got so quickly attached to the theatre actress, only to be like, 'oh, holy shit I just like the idea of you, and I didn't really like you, and I got so wrapped up in my fantasy of how lovely this idea was to carefully look at this reality, and now you're emotionally wounded for it?' That is SO Sunny, another soul invested in ideas of perfection, sentimentality, and goodness, in which they're almost a novelty to somehow be pinned down to a physical culmination like a butterfly hung up on a wall. Observed, but never truly touched.
Dorian's thing is that he's so subtly self loathing, while Sunny is super transparent about it, so there's a difference there. Dorian tries to outwardly 'own it' like Lord Henry does, then has a mental breakdown later before going out for fucking tea or something. I would say Sunny is *generally* more well intentioned than Dorian, but it's difficult, because there's still a degree of self centeredness that fucks everyone over they ever could've cared for.
As a character, they both also have thematic aspects of 'purity being corrupted,' and through both stories, this is really emphasized through Basil's perceptions of them, which transfers to how the audience views Dorian. It's kind of similar to the Nick-Gatsby dynamic, but in a less deceptive portrayal, with how this person (Dorian and Sunny) could never have been this emblem of purity and goodness you wanted them to be, and that they've likely always been given more credit in that department than they deserve, which makes their downfall hurt all the more. Projection of desires, if you will.
It's my reblog, so I'll spoil if I want to, but the Neutral endings are haunting in that they are the endings where Sunny and Dorian unite with how their characters turn out. The True Ending of OMORI, in my eyes, is if Dorian stopped trying to be a second Lord Henry, and took Basil's hand when he offered to pray for him. And in both stories, Basil was ironically the one who truly acted as the genuine symbol of purity, staying unchanging and faithful throughout the whole story, his only fault being that his flattery and goodwill stoked flames of delusion, and making it their mission to remind Dorian and Sunny of the person that they could be, if they tried to change and move on.
(Also, it's funny both Dorian and Sunny are given the "baby boy, baby!" treatment by like, everyone, lmao)