Like the taste of an adult villain Bakugou who becomes a villain because he agrees with Stain's ideals so he starts killing heroes to prove they're weaker than him and not worthy (basically same as Stain). He doesn't do it often, but when he finds a target he hunts them.

He's also helped to save heroes that he HAS deemed worthy. That's how he becomes the crush/rival of Pro Hero Deku who is conflicted about his feelings for this infamous character.

Romance twist: Izuku falls in love with the civilian version of Katsuki who kinda slowly gets Izuku to agree with his views
Or
Katsuki starts to slowly agree with Izuku's view of things.