Like, I'd love to chalk it up to highschool versus college, but that gap is too wide
I think its bcs here, hes around muryeong. There, he's around Muheun. And here he can't see ghost as well, there bound to be changes when you were just suddenly thrown into supernatural world that actively hunts you ╥﹏╥
Now that i think abt it, poor seungjoo..
You see him around Muryeong in the og and you see him prior to his spirit sight awakening, and that doesn't explain the way he looks changing so drastically.
Well idk i dont feel hes that different? No you never actually see how he acts around muryeong in night of muheun, only his thoughts, we didnt even see muryeong there other than one picture that shows his eye. We hear seungjoo internal struggles a lot there, which mostly came from the ghosts and muheun, but not really here.
And appearance.., just different artstyle? This artstyle is more cartoony while night of muheun more like semi realistic with korean-inspired-kpop hairstyle, the ml also has this problem. But muheun is pretty much the same, so again idk.
i just realized seungjoo (mc of night of the unmarked) has shown up so many times here already. he looks completely different. personality too