Alright, let's break this down.
OOP realizes his personality is the reason he can't get a date, so he sets out to change his personality to be more appealing. Specifically, he copies a fictional character who's more liked online. Makes sense, he's been copying manosphere incels before this, so we know already that this is how he learns to act like a person.
Breaking down his attempts at flirting:
He deletes his old profile, specifically citing that he now has the profile of a "pathetic wet rat of a man." This includes: an interest, what he's been reading lately, a picture of him in nice clothing, and "zero attempt to seem attractive or confident" in his own words.
Based on manosphere and incel circles, we can deduct that "seeming confident" likely meant "acting like an alpha" or being an annoyingly overbearing asshole with far too much self importance. "Seeming attractive" is, therefore, likely to mean that he was attempting to "looksmax" or whatever they call it now, and appeal to very basic forms of traditional masculinity as a crutch for what he calls a "very ugly" appearance. Mind you, he did show us a character that looks exactly like him, and no manosphere podcast or incel forum is going to call that man attractive by their standards.
Next, we get the gal reaching out. Based on his reaction to her making the first move, we can deduce that he's never been the one approached first. She asks about his reading material, politely and (we can assume) genuinely worries for his health, then makes a connection to her own life. This is how normal humans interact with each other.
OOP is so unbelievably flustered by this that I'm scared to ask how he was approaching women before. He says that he types in a "pathetic" and "honest" way, using the words interchangeably. Being honest is a dangerous step towards being cringe, and he's "tightrope walking" between the two. This is how he views talking about his health, family, and hobbies. He views speaking on his interests as inherently negative. Being "aware" of his family's health issues and how to be proactive about his health is cringe. Mind you, he's deliberately not telling her that he was doing "autistic research" so we can assume that his definition of "cringe" is "showing an earnest interest in things that spark curiosity" which is... A take.
Next, the two of them have a multiple day back and forth, talk about their lives and as OOP continues "being whimpy" she continues to reply. Clearly, whatever he thinks of as "a wimp" is what this gal thinks of as boyfriend material, because she starts to drop hints about going on a date, which he doesn't pick up on. If repeatedly mentioning a really great coffee shop is too subtle for him to even pick up on, I worry what he thought was being "direct" and "confident" all this time.
The gal then takes charge again and directly asks him on a date. This causes OOP to have a genuine panic attack for 35 minutes.
He's had tinder for a while and never gotten a date, so we can assume he's been unbearable for a decent while prior to this, and now his first experience with a girl being interested causes "a full system shut down" for over half an hour. In that time, the other party recognizes she might have been overbearing herself, and backs down, likely assuming he wanted to remain friends or she came on too strong.
OOP then reassures her with a classic "no its okay I'm just so shocked you like me that I completely had a full system break down for like 30 minutes" which, if I'm honest, does sound kinda cute. Clearly, this is her "type" so to speak, and she eagerly looks forward to their date.
On this date, OOP dresses nicely (in his cosplay gear. I guess) and mimics the mannerisms of Viktor Arcane. A quick search and some time wasted shows me that Viktor is somewhat fidgety, often drops and resumes eye contact, and uses one hand for gesturing when he talks. Though that last part is because Viktor uses a cane. He then says things that are "mortifying" because of how honest they are.
So to recap, we can assume that OOP showed up for his date dressed nice, visibly nervous, and was open with her. In fact, he seems to think that being honest at all is some kind of repulsive turn off, from a guy, that is, because he isn't even questioning it from the gal he's talking about. This is some incel weird law where men have to dress casual, be overly confident, and closed off.
No wonder THIS is what got him attention.
He basically managed to copy a fictional character so well, he became a very basic first date experience. He wore nicer and more professional clothing, looked nervous but engaged, and tried to be as honest with her as possible. He talked to her about his life, family, and interests. He told her about his day, talked about hers, engaged with her directly and showed interest. He waited for her to make the first move, then eagerly accepted, and clearly, he was exactly her type, because she reached out first on top of being the one who asked him out.
Yeah, I'm not sure what they're teaching in incel schools over on 4chan, but that's very basic Dating 101.
TL;DR: Local incel discovers that being open, sharing interests, talking casually, and genuine honesty is not considered pathetic, but in fact how normal humans often act in romantic situations.