I have to ask, why is your view on mha female characters nonsensical? Not to mention your reasoning behind the "sexism" of mha makes zero fucking sense 😂.
I don't really see how it's nonsensical. Hori clearly has a pattern of killing and or maiming his female charters so they're no longer involved in the story. The only even somewhat relevant ones he keeps around are Toga and Ochako whose character goals are heavily influenced by their feelings for Izuku.
Like to be honest idk what definition of sexism your working off of to not see Hori's recent treatment of female characters as sexism. He made both Lady Nagant and Star and Stripe to be these very strong women, but neither serve any purpose but to lose to male characters and never be seen again, or in the very least never be helpful again. They were essentially eye candy and nothing else.
And I'm not even saying that Hori is doing this on purpose. I doubt he made these characters with the intention to make women look weak, or incompetent. I think he's just getting tired of doing this manga and as (what I assume) is a straight guy, wants to make it a little fun by having some attractive women to draw as he pushes on toward the end. I don't think he realized he's repeating tropes that are sexist.
Nor am I saying that an author can't ever hurt of kill of a female character, just that if they're going to do that their has to be other female characters that fulfill similar roles that aren't sidelined. Like Star and Nagant wouldn't be an issue for me, if Hori hadn't already sidelined his other women, like Miruko, Ryukyu. and Mount Lady after the War Arc. None of them died and some even had less sever injuries then the male characters like Enji, but besides Mount Lady, who got like a handful a panels when they raided the mansion looking for AfO, have been almost completely absent.
Sexism isn't the just the egregious stuff like having a giant breasted girl in skimpy clothes (which he actually does have with Momo). Or having panty shots all the time. Sometimes it is just the disposability that those characters have. They just aren't treated by the narrative as important.
I mean, he also has Mineta--a character who is a giant sexist perv who sexually harasses his female classmates and it's played for a joke. He may not have done something like that in quite some time but that's not because Mineta had a mini arc where he learned sexual harassment is violating and a crime. He just stopped doing because the manga got serious and that'd be such a ridiculous tone shift Hori won't even do it.
So even if you ignore all the other stuff--Mineta alone makes mha sexist.