(sry this took a while to answer bc i had to think about it lol)
tbh i could see so many different possibilities being in character, esp depending on the details of the au. But like, assuming this AU is as close to canon as possible while still being set in the present w/ current identity politics and a gay community etc, yk both still have traumatic histories, griffith still has a dream that requires marrying a woman, etc etc, I can maybe throw out a few ideas. tho again like, nothing set in stone.
I guess ultimately I really want them to be each others’ realizations.
I like the idea of Guts’ being a slow realization that kind of sneaks up on him, where first he realizes that he would absolutely be dtf Griffith and it’s not til after that realization that he figures out that makes him gay. Like I mean he’d fall into that “it’s not guys, it’s just you” cliche but he eventually realizes that no, actually it is men.
He might try experimenting too – like surely it’s just because Griffith looks androgynous, so being with a woman would be better – but nope, doesn’t work.
Might be worth mentioning here (tho i’m sure u already know this) that I hc Guts as gay rather than bi bc Miura did a great job of making his interest in Casca feel super inauthentic to me lol.
Also I think it’s fair to assume that his csa trauma would lead to some discomfort here, but at the same time I don’t think he’d consciously like assume all gay people are predatory or even assume his rapist was gay and not just a pedophile. He might be uncomfortable being checked out in bars at first, and I feel like he’d be prone to worrying that his sexuality makes him specifically more likely to hurt someone bc feeling like a monster is kind of a canon issue he has, but he’s smart and fairly self aware and wouldn’t make it anyone else’s problem for the most part, barring like flashbacks during sex or smthn.
Also he’s tough enough that he’d never really feel like he’s in physical danger with anyone else. So assuming he’s in a good place in his personal life (ie not in a walking disaster “don’t touch me” phase) I don’t think he’d show any discomfort. (And I mean in canon the first time we ever saw him relaxed and happy was while having a water fight with a naked dude who he thought came onto him when they first met a few days earlier. I really don’t think it would be a huge issue.)
And overall I think he’d be fairly low-key about it. He’s gay but it’s just a description to him rather than an identity to build his life around. He wouldn’t be closeted but he wouldn’t be out to everyone in his life like, idk coworkers or w/e. Tho eventually I think everyone would realize because I think he’d kind of want to show Griffith off lol.
Griffith I could see like, simultaneously knowing he’s gay all his life and refusing to fully acknowledge it. He’s gotta achieve a goal which requires a certain image which requires heterosexuality. Maybe he’s not actually attracted to women, whatever, but that doesn’t actually matter as far as he’s concerned.
So with Guts being his realization, what that means is that Guts is the breaking point where Griffith realizes he’d rather have Guts than the dream. Yk, like in canon, but with a) no torture chamber, and b) the addition of this realization leading to the larger realization that he can live as his authentic self and be happy.
Like I’ve mentioned before that in Berserk you have this dichotemy of the dream/het marriage/emotional repression vs guts/emotional expression and yk in a modern AU you can add coming out to emotional expression.
Like we’ve talked about this b4 but I’m saying it again bc I love this idea where Griffith realizing he’s in love with Guts and would rather be in a relationship with him than achieve whatever his modern AU dream is is like a catalyst for dropping the image of respectability and ~finding~ himself. He’d make a bunch of gay friends, start experimenting with more gnc looks, volunteer at pride, go to protests, etc.
Though if his motivations for achieving his dream are similar to canon (mb not the whole for the sake of the dead thing, but yk guilt, to assuage a feeling of inherent worthlessness, to justify things he did to achieve it that he’s ashamed of, w/e) there’s also plenty of room for some angst and drama in between that realization that he wants to give it all up for Guts and embracing a new life. Some “am I selfish/terrible for choosing Guts” soul searching or w/e.
ALSO I feel like modern au griffith could’ve been fairly gnc as a child – wanting to play with girls’ toys, singing along to britney spears, saying he wants to marry the disney princes when he grows up, wanting his hair long, playing dress up in dresses, etc – with some kind of catalyst that hammers home this idea that to get the thing he wants he has to police his behaviour and be like everyone else. this is self indulgent but i just like this concept of like, knowing what you’re about as a kid and then having to unlearn everything you’ve internalized since then. it’s an appealing narrative to me.
And like I could see Griffith’s trauma with Gennon actually affecting him and his opinions wrt sexuality/internalized homophobia more than Guts’ trauma affects Guts, mostly because Gennon was such a goddamn evil gay stereotype in canon, plus Griffith’s own self-loathing compounded w/ the idea that he’s always sort of known he was gay = a secondary motivation for trying to embody the image of a heteronormative ideal, to distance himself from the idea that he’s anything like Gennon. Like Griffith’s trauma comes with a side of effeminate stereotypes and ostentatious homoerotic castle decor, etc. But I don’t think it’s necessary either, like it’s not something I’m super interested in exploring and hey maybe modern AU Gennon is less of an offensive stereotype. and/or Griffith is v socially aware and capable of recognizing that Gennon isn’t representative. w/e, kind of a take it or leave it thing I guess.
Also I’m not really envisioning these 2 concepts (guts and griffith) in the same story lol. Maybe they could fit together but I didn’t really think about it.
And again like, I’m just throwing stuff at the wall lol, not saying this is my Official Take on Sexuality and Characterization or w/e.