Even in the villain showcase arc in the manga, Spinner doesn't get any of the same standout character beats or intriguing power upgrades that his cohorts in the League of Villains do. However, while there's some clever visual humor going into Spinner's character, that's all he's really showed in the story. Having Stain, who's basically a mix of Punisher and Daredevil, inspire Spinner, who's basically a mix of Stain and the Teenage Mutant Ninja Turtles, is pretty funny. In a way, Spinner is a visual callback to the Teenage Mutant Ninja Turtles, who were themselves a parody of ninja mutant comics like Daredevil and X-Men. Hilariously, Spinner's Quirk makes him a human lizard, while his costume is clearly styled after Stain. Spinner, who later joins the League of Villains after being inspired by Stain, considers himself the embodiment of Stain's legacy. The hero killer Stain made a big impact in My Hero Academia, both on the readers and the characters. Even in a world where anyone can be a hero, it seems like some people are still just average. There's plenty of possibility in a character that just works harder than his more talented peers, but we haven't really seen that in the anime or the manga. His relative plainness has been played for laughs, and has largely been the only character detail that he's gotten. It's not the most exciting Quirk, but in fairness, Ojiro isn't the most exciting character. Ojiro's a martial arts practitioner with a Quirk that gives him a prehensile tail. Still, even the more minor characters have still gotten to shine more than Ojiro Mashirao. class 1-A, don't all get equivalent screen time. Even the ostensible main roster of characters, the students of U.A.
There are a lot of characters in My Hero Academia between the pro heroes, the villains, the teachers at U.A., the students at U.A., the students at other hero-training high schools, and the unrelated vigilantes, there's simply not enough time to fully explore every character.