
I find it hard to ship either, but grey hair guy does make a more convincing argument. Black hair guy feels like the spirited away/abducted route. Now we find out about MC's constitute, no one will put in the effort to find MC except grey hair guy.
The fact that the mountain spirit decides to come now instead of coming into MC's life earlier tells me he's actually come to collect his due debts. My guess is since he's already been fading from existence, and MC is going to be like a bride whom worships their god, or he's come to collect his remaining life force back.

I do question why didn't the spirit come earlier. If it did thn mc wouldn't even have chance to meet the gray haired one in the first place. The way this spirit is erasing and manipulating all the memories of the mc about the people around him to use it to his advantage is so shtty. Definitely gonna take his soul but thn plot will thicken and spirit will fall in love and would do anything to keep mc to himself even if it meant k!lling.
This manhwa should have more tags on it tbh

Idk about the black haired ML to be the Mr. Right, but certainly gray haired one isn't for MC either. Did you forget how poorly he treated MC? He just shoo MC away after recklessly taking pleasure from MC's body just because his friends is coming. I get it he's straight, but that didn't make an excuse for him to treat a gay man like that. He's just immature and kinda self centered. Because, look how easy of him to blame MC in every argument even after he realized he's in the wrong.
There's no real green flag between both of MLs

Well from the most recent chapter where it was talked about their past and how their relationship started ,you could see what I did when gray haired guy's pov was shown. Idk if y'all missed it or I read too much into it but he mentioned there that mc didn't want anything serious with him so he'd do it with him for pleasure only. That's how FWB works in most cases irl as well. No feelings attached or to do extra stuff or else other party can take it in wrong way
I don't understand why y'all are shipping mc with black haired more than the gray haired one. It's clear mc's memory and thoughts are all getting manipulated by that spirit and also the people around him are being controlled bcoz of it. The fact that gray haired one was the only one who could see him past the "bad vibe" that was caused during the accident in childhood should mean something. Idk I still think gray haired one is better choice. Also not to victim blame or anything but Mc himself said he never did it with any guy either but he also didn't mention it to gray haired one about it when the gray haired one was clearly a straight guy this whole time. Mc was scared of losing someone who could finally see him for him so he did everything to keep gray haired one by his side. If he was hurt and felt uncomfortable he never told that to gray haired one no matter how many times he asked. Gray haired one was clearly entranced by mc and he was the only one who could see the actual aura of mc. Not to mention he's the one trying to keep mc safe from that spirit constantly. Idk y'all I don't like this spirit thingy. Whether mc ends up with gray haired one or black . I will stick to my opinion.i still have so much on to say but I'll end it here