I feel like they would be good together, But I think one of them is going to die or they'l...

Nah they won't die. The focus is on getting revenge so betrayal is definitely going to be the main thing. I think it'll come close to dying, but seungrok won't die for our sadist MC probably. Going to jail could be an option, or maybe not. Ms. J and that police dude will definitely be fucked up by these two though.

Pretty good explanation, Maybe they won't

Yeah it's not game of thrones Haha so probably not. What would be the point of making them go through hell just to have them both die at the end? They should be the fucking kings. However, if the "queen" dies, the game is over. I think the clues lie in the chess instructions that we were probably too lazy to properly read and understand in the earlier chapters (speaking for myself)
It'll be hella amazing, if the police officer worked with them to unravel some other big corruption in the police force itself. And kinda lets them off the hook.

Thank you for this explanation I get the story more I was a bit lost

No problem! It's an interesting story, and one of the few mangas that have a good plot (unpredictable) and mysterious (like mad place by junho) have fun!