Edit: I checked the US trademark page and there are only 6 registrations for Vantablack and none of them are for fictional characters. There are three that seemed to be linked to shit bag artist for name and usage of the special "exclusive paint". The other three are for different business usage in naming products they sale. Two for alcoholic drinks and the other one is for nail polish.
Dude, next time actually post evidence of it when you make a posting like this.
Screen grab of the shit translation: https://i.imgur.com/me9yXsz.png
Wikipage about the character in question: https://myheroacademia.fandom.com/wiki/Shihai_Kuroiro
Edit: I checked the US trademark page and there are only 6 registrations for Vantablack and none of them are for fictional characters. There are three that seemed to be linked to shit bag artist for name and usage of the special "exclusive paint". The other three are for different business usage in naming products they sale. Two for alcoholic drinks and the other one is for nail polish.