My theory.

All I want is to JK own up and to face the consequences of his actions. I think the short time frame of two episodes wasn't enough. Him losing Dan, his championship(?) or team members at the gym, wasn't as satisfying. Some may say that's redemption enough, but is it?
I mean maybe the author is going with having it show how someone can get back up on their feet with hard work. JK healed quickly because he did his therapy. He never stopped training etc. And really what he needs to show is remorse and at least enough guilt to own up to his fuck ups. Asking for forgiveness etc to everyone he did wrong. Showing a changed man.

But definitely I think for Dan being the complete opposite in they both grew up poor and in very similar situations etc, yet having different reactions on how they handled their trauma is now, refreshing from what we see. Granted, JK did have horrible parents that beat and abused him or simply abaondoed him. Dan's parents are dead and he grew up with an old grandmother that showed him kindness. I'd like for Dan to have enough assertiveness. He isolates himself so much.

If his grandmother dies, I think if he learns to rely on others when he needs help, would be a nice touch. He doesn't need to face his shit alone.

My theory is that this is where it's gonna go. And minhwa is gonna make it where JK genuinely is kind and compassionate towards Dan, being the only one there for him when he feels most alone. Stubbornly helping him as Dan tries to push him away because he's alone.

I think if Minhwa does this sort of redemption, it'll be very similar to what happened in a danmei I am reading called Joyful Reunion. *SPOILER!!!!!!*

The ML treated the MC poorly and was angry often. He beat and would laugh at the MC when he somewhat torture him by healing his voice using poisons. The poisons would cause extreme pain and he'd laugh because everyone looked down on him (ML) and humiliate him, so now he had someone he could bully. Regardless, he still healed and saved the MC's life. But he goes through heaven and hell to protect him, grows soft and gentle with the MC. He had a very soft side anyway and always failed as an assassin because he was too soft, but hides it under his grumpy self.