Going to just give this Five Stars because there are quite a few good character moments. Mostly regarding the Todoroki family. There's an attempt to flesh Aizawa out a bit more, and it's alright, but I think it's not done as well as it could have been, because it mostly involves around a) a character we've never really seen and b) a character we haven't seen in ages.
The volume is actually a little weak in some areas. The training with Endeavor and his agency mostly happens off-screen, and the main fight for this little arc ends up feeling less of a big deal than Gentle, whose fight was pretty short but who felt more relevant as a character overall. Ending here could have been easily replaced with a Nomu or something without really changing anything. He only ends up being "relevant" to me at all because he's one of the Adventure Mode bosses in the second BE Memory for Vital Bracelet....
Todoroki's sister's boobs look great on the back cover. Uraraka looks good as well, but it's a bit unfortunate the framing cuts off her hips. Burnin is always hot (heh) every time she appears, which is unfortunately not very frequently (and is another reason why I wish the Endeavor Agency Arc was longer...). Uraraka and Hadou both look great on the cover for Chapter 248, but it runs into that weird thing that happens a lot in Horikoshi's art where it's obvious he's trying to show off armpits, but these girls are in skintight suits so their armpits are technically not as lewd as they maybe could be. Uraraka looks good again in the first panel we see her updated costume in Chapter 253, but it also kind of makes me wish her hair color was lighter in color, as she looks so much better in black-and-white here and other such pages. The next page has decent little pics of Yaoyorozu's ass, Jirou's legs, and Ashido's cleavage. The cover of Chapter 254 has Uraraka and Yaoyorozu looking especially nice in these super-detailed costumes, but I feel vaguely that Toga's simple black thigh-highs steal the show. Fuwa from Class 2-A is pretty hot, but I doubt we'll see much of her in the future, if at all. In Chapter 256, we see Ashido with her hair matted down from her Acidman technique, and she actually looks way better this way.... There's a good shot of Yaoyorozu cleavage shortly afterward, as well. Nana's muscular groin looks amazing in the scene where All Might is theorizing on Deku's next Quirk unlock. I already gave a blanket statement regarding Burnin, but her thighs on the cover of Chapter 258 are important enough to mention specifically. We see a brief image of Mirko on the last page.