
actually, wait. I just read this recently. it's pretty new though, i'd save and let it marinate for later.
https://www.mangago.zone/read-manga/yusha_no_haha_desu_ga_mao_gun_no_kambu_ni_narimashita/

Yeah you know how in father-daughter manhwas, the father usually already has his own son but he treats his own son coldly (or just indifferent) until the (usually adopted) daughter comes to brighten their day or whatever. The father only starts treating his son like an actual father once the adopted daughter comes in.
I want the villain father repenting for his mistake of being indifferent / neglectful to his own son
Father-daughter and Mother-son trope is too common in isekai manhwa. Mother-daughter, I know a few and have read those. But father-son?? Is there isekai manhwa focusing on father-son bond?