It truly is an oof
Are we reading the same thing? Um.. Nakyum could have escaped way much before, he did try in fact, but he didn't want to and stopped in the middle of it. Nakyum realized he doesn't have a place to go and no one to lean on, he has food and a roof with Seungho, he is not even a slave. He realized that indeed Seungho take well care of him. So yeah, again I'm wondering if you pay attention when reading.. Lol. Escaping isn't in Nakyum's dictionary anymore, since long begore.
He just doesn't have the brains to strategize an exit. Poor boy is too docile like the typical MC in these types of stories.
I wouldn't call him "typical". His behavior is well justified. He is a low-born, an ignorant, doesn't have a family and again as I said, no one to lean on. His life was miserable even before he met Seungho. He was living as a drunker day and night. Now, recalling.. Young boy, ignorant, alone. What do you expect him to do? Don't blind yourself judging the character as if he doesn't have a well-structured background. That's what I like about this Manhwa, characters doesn't act the way the do just because. They all have a background.
The painter could easily escape now that psycho lord is "sick". Steal some finery to sell and GTFO. But I suspect he is far too down the line in being broken and having Stockholm syndrome to do this.