
it's the person who kinda gave him another reason to keep living, dude has PTSD and depression so it must be a big thing to get
Hyeon gave him a new place to belong to, make him met new friends, gave him purpose as a restorer, gave light to his abilities and even give him romance
Although hyeon has like motives behind to all of those, it still helped yiseon as well so kinda what he didn't ain't that heavy I guess

Until Yiseon decided to commit suicide in front of him (I'm going to speak about the chapters before the suicide chapter). Hyeon sees him as some kind of commodity or property. It was as clear as day that Yiseon developed feelings for Hyeon, but I can't say the same for Hyeon. His affection was ambiguous. Remember, Hyeon's main motive was to recruit him into his group? And all the things, such as new friends and a new purpose to live, come as byproducts of that. I'm still trying to understand: when did Hyeon fall in love with Yiseon, or is it the pity that turns into love? You can argue that both of them used each other for their own purposes, but you have to keep in mind that Yiseon's was suffering from depression and PTSD. Well, whatever. In the end, I'm happy for them nonetheless.

tbf its likely lots between them since the last dungeon has happened and it either was cut or hasnt been shown. i do also think hyeon genuinely cared for yiseon for a good amount of time he just cared about him more similarly to how someone cares for a pet.
considering that yiseon was fully aware of hyeons real intentions and has been closest to hyeon for several months i think itd be safe to regard yiseons judgement as quite fair. he also probably hasnt fully forgiven hyeon, at least not yet
Is it just me, or did Yiseon seem to have forgiven Hyeon too quickly? Hyeon did nothing but cry and plead before Yiseon. Yes, they look adorable in the new chapter, but I would have preferred to see Hyeon go through a little more hardship.