update as of 7-28-2025:
TLDR;
He is a slasher, unstable chronically-online loser, 7'3 (222cm) monster, doxxer/hacker, and extremely obsessed with you, the player. He is, in fact, in the male yandere category.
In the perspective of the player, you walk into one of the hotel doors to do your job of convincing the monster to leave the room. However, you don't see one in sight, and the door shuts behind you before you realize. The walls are covered in pieces of paper, pictures and writings of some sort. It unnerves you.
He's a big fucking immortal monster of unknown origin. He has an emotional support axe he grips onto at times, when he's easily excitable. Kind of a dumbass, REALLY SILLY TBH.
He's your biggest fan!!
He never really had a name to refer to him as. He mentions his username online was NauseAxe_404, and not really a real name since he's an internet loser. The game files label him as "fan", probably short for "your biggest fan", which is how the dialogue displays his name as.
To put it bluntly, he's your stalker. Utterly obsessed over the shit you wrote and posted online. So much so that he knows what you look like, where you live, everything about you.
He's also a bit of a yandere. I'm underexaggerating, he's a full on yandere. He loves you way too fucking much.
You ever heard the trope "I can fix him"? Unless you are okay with writing the shit you aren't interested in anymore, making it hundreds and hundreds of pages for him to live in. Or if you can live with a 7 foot tall monster man looming over you, urging you to write your work 24/7. Then you probably can't. And you will probably die no matter what, being crushed to death due to his obsessive nature.