Responses
You're right he did gloss over his past like "I'm okay" but he did say from chpt. 4 that he would take revenge on those that had put him in hell, and then we saw how he was broken down from not becoming level 5. Sure he did get sent to Rath'na and his trauma didn't hinder him because "It was something I had to do" and that he would survive one more day in hell just so he could kill the perpetrator.
Did you see the look in his eyes; that was scary! It's not so much that I forgot that he was stuck in that place with the helldogs for a long time, it's just that the affect it would have on him didn't hit me that hard until I read the chapter where Maiden went inside his head, and this chapter. Because his behavior seemed normal and I got swept up in the action, I thought he was at peace with it and glossed over it; but now, I'm starting to think otherwise.
I haven't seen many action mangas that address things like Hanbin's past, so I'm curious to see how it will go forward regarding his mental state. If he hasn't completely gotten over it, then I hope that he'll finally be able to find peace with the help of his friends, because, thinking about it properly, that's heartbreaking.
It reminds me of that movie that Tom Hanks played in where he worked for Fedex and something went wrong with the cargo plane and crashed in the sea, putting him on an uninhabited island. There were some scenes in there that really tugged on my heart strings.