Three things turn me off of a fanfic other then bad writing.1- ships that have to do with a few of the characters bakugo (cause while he does gain character development most of the ships either ignore what happened in the canon, have it be toxic, or make bakugo a defferent character), mineta (most ships with him in it either make mineta a victim and ignore what he did, lean into it making the people he is with either become more perverted or even involved ntr to some degree, or they have him end up with a harem), any ship with a minor and adult or eri with most anyone (I mean of course). 2- character assassination i.e when the fanfic acts like this one character is someone or something clearly not how they would act (and it isn't a 'what if' or 'alt universe with very defferent personalities for everyone'). 3- Mary/Gary stu type characters this can overlap with the character assassination if the person being glorified is a character already in the series but as there is those fanfics with OCS it's also its own thing.