Schirochan

I personally hate bestiality or any furry type shit. Or if an art style isn't good or if translations are bad I can't read it. Or if an manga has wayyy to much text shoved into it I normally don't like to read it

I will never read doujinshi. Never. Just the thought makes me sick.
Other than that, there are basically two things I absolutely despise and won't read under any circumstances: age gaps, and possessive characters. Ugh.
(There's also a 99% chance I won't like megane characters so I tend to avoid them too, but that's just a preference and it's mostly because they're boring)

Too much drama and too much misunderstanding like hello dumb you have mouth for solve everything so please use that,and the weak partner like he hurt you and cheating on you but you still want him and easy forgive him you definitely blind and no brain and the last is an omegaserve my eyes pain already about omega x alpha ...I need fresh start with omega x beta or beta x alpha or alpha x alpha or whatever as long they have kids...I'm sorry i too much talking

weak , crybaby , manipulative , bitch , girlish uke

and manipulative seme
I'm done.

Teacher x student

The animal ones like I I don’t find a wolf and a cat fucking as...cute cat ears ok bunny ears ok. But when the fur and wolf mouth come into play I can’t handle it.

I can't stand teacher and student mangas, or those annoying, blushy girls in mangas. I especially hate the annoying side characters that aren't needed in the story. Lying in romance mangas are also a big no no for me. Last, but not least, tsundere girls ( but i'm okay with the ones that don't hit, aren't calling the person stupid all the time, and have this stereotypical body shape ; when they're short and have their hair down or in a really annoying hairstyle

I dont like it when characters scream too much because then there's so many text bubbles , if the texts are light and stuff like that. I just personally dont like it because things like that give me headaches easily because it (strains?) my eyes

Romantization of rape, abuse, etc. Nope, I'd rather those topics be taken seriously, not as an excuse to get uke and seme together so they can live "happily ever after".
Mind break, it genuinely scares me when mc has his limbs amputated or has no control/say about his life anymore.
Anything involving animals or children.
A whiny, girly, weak uke. I ain't got time for them.
I ain't got time for a cold, controlling seme either.

Bestiality (unless it’s only ears & tails) and shota make me so uncomfortable
i‘m also tired of whiny, tsundere uke...
but what i hate the most are cheating stories where the „victim“ decides to forgive their scum lover. I still read them in hope of finding a good one tho
I‘m okay with miscommunication but not to the point of it being dragged on for so long and being used over & over again as an excuse to continue a series (i‘m talking to you Hidoku Shinaide and Kurokoneko series)

I‘ve noticed that I also don’t tend to read lengthy yaoi with the supernatural tag. Don’t know why, since i‘m ok with short ones

I cannot stand loli or anything that has constant underaged characters having sex with grown men, then there’s furry shit, in my opinion when you add the sex it just turns into beastiality, and that’s disgusting. Now there’s cliche tropes, easily manipulated characters or just characters that have no will to fight back really bother me. I guess I like to relate with the main protagonist, and if they’re just a complete utter push over that doesn’t even try, i person get aggravated

I really hate it when they add unnecessary drama to the story(or some third person) .
I also can't read omegaverse it's just too unnatural(ofc lol) and weird.
ı don't like it when the uke is weak small naive or innocent , i just get irritated when i see one

You know what's funny i literaly got bored of the regular fluffy, echi and that most of the rape then fall in love plot in yaoi story so i started to read yaoi with a dark themed but it backfired me bc it's a fucking necrophilia and (kinda) cannibalism story yes there's a necrophilia yaoi story where the mc fuck a real corpse and it traumatized me so bad that i can't read yaoi for almost 5 or 6 months to sort of my thought it was so dark he also eat the bones/ashes of his family members, the point is that story is a serious fuck up and from then on i am being careful not to read dark yaoi, oh i also hate incest and infidelity that's a big no no no for me

I only like yaoi where the couple is happy and in love. So I mean, seme takes care of and loves the uke, and the uke repays the same. I love when there are a lot hugs, kisses, cuddles and sometimes a little bit of an unforced sex. In other words, I like manga where there are proper romantic relationship. I hate mangas with a pattern: rape-->love, abuse-->love and where the relationship is based only on sex and there is no proper development of relationship.

Beastiality

This.

really slutty ukes(& semes) it's dirty and not cute. i don't like incest...so many people romanticize that sick stuff, HUGEE age differences, i hate when the author makes the uke really innocent, timid & feminine it is NOT CUTE to me at all you are a man act like it, i'm over tsundere characters who take the tsundere role too serious(like senpai from Koisuru Boukun and others) i just cant and never will take Beastiality serious its...weird. theres more but yeah.

Mpreg and bestiality. I find it disgusting and stupid

Hmm, I tend to avoid omegaverse, comedies, art I don't find appealing, too cliche, when at least one character is too stupid to live, stories where one of the characters has a kid, bestiality, male pregnancies, too dramatic, and I'm sure there's more, but those are the things I remember I tend to avoid.

Bara uke , hairy character , and weak personality character

I just wanted to reply to your comment because i'm kind of bothered.

Do you know what doujinshis are? They are self-published works not affiliated with a company...Doujinshis can be an original story or a story involving characters from another work. And I get what you mean when you say "doujinshi" in as stories that "ship" characters or stories that are not part of the official story, but doujinshis are not limited to just that. So I think using the right words to express your thoughts would be much better than dismissing all doujinshis in the world.

Vampires. It’s disguting

I can only think of Dark Heaven right now :/

Playtime with Hakdo.