In this chapter, we learn that Ho-sun is an "enhanced human" , just like the man who amputated his hand and left him a hole in his body. He's just as strong and can regenerate his own hand and body parts as well. The only weakness is his brain, which means that, as long as he and Ho-Sun keep it safe, they're "the immortal human weapons" . This means that they can beat the "shit outta you" as much as they want, but if they don't keep their brains safe, then they won't be able to beat Ho-Sung as well as they can. This is a big deal, and it's why the two of them are talking. They're both "enhanced humans," but the gap between them in power is so big that if they hit each other, they could both die. They should have asked each other if they know each other's families, and if they cause the other to be unhappy, they should take responsibility for it. Ho-sung is his family.