Responses
Nope, he got none. Because unlike Reynold who had a legitimate reason to hate her (He over heard her wishing for Yvonne to never be found when they were kids) and as a reader and a person I sympathize his reaction (Which was overkill), Derek disliked Penelope because he fell in love with her. He didn't want to admit that he likes his step sister, so what do bullies do to show they like that person? Bully the crap out of them.
I believe that's why he never got a redemption art. Unless I read the novel wrong or the webtoon artist drcides to changes it up.

guyss do we get a derrick redemption arc? or will he come clean about his feelings? spoilers pleasee