The only way Jaekyung can be redeemed is if him, and ONLY him work on their relationship between him And Dan.
Like Dan, finds somebody else, Jakeyung sees them, he gets jealous and tries to hire him back. Dan obviously says no and And Jaekyung gets pissed off. He sees his old ways don’t work and actually tries to fix the relationship. This is the only way I feel he could be redeemed.
there are probably alot here https://www.mangago.zone/home/mangalist/206/
Saezuru tori wa habatakanai. It's a story about a yakuza leader and an ex-cop that joined the Yakuza. I highly recommend it if you haven't read it yet.
Small nitpick but why tf are hyesung and Dojin the look same age when 17 fucking years has past? Like at least give them a little eye bag crease or something because when I look at their interaction with byul it looks like siblings talking to each other rather than parent and son.