He had to watch someone he’s grown to care about and feel romantically for die many, many times. He himself has had to kill others he’s cared about over and over. He’s died in many ways again and again. That’s traumatic. That can completely change a person. It’s not like he started treating Hohyun horribly from the start. He’s in the apocalypse and doesn’t have the time to coddle Hohyun anymore. Ki’s mental decay was displayed very clearly throughout these chapters. He’s starting to wonder why Hohyun is behind all of this. Why is Hohyun putting them through this shit existence over and over again. It’s definitely not Hohyun’s fault, but it also isn’t Ki’s either. He has tried over many, many lives to find other ways to save hohyun. He’s said that, and it’s even shown how distraught he is when hohyun has died in the past, or the possibility of him dying now. There’s no choice but to act hostile because kindness in however many lives before has clearly not worked. Ki is doing all he can to keep hohyun alive, even if that means he’s being an asshole about it. He clearly is not all there.
Sadly, it’s not as easy as just “waking up and accepting reality”. Obviously this isn’t real and never will be so there’s no point agonizing over it, but it’s fun to think of the possibilities and what it would be like if you were in the story! Trauma wouldn’t be trauma if it was as simple as accepting it. Mental illness that comes from trauma also would not exist! Personal TMI experience to tie into my claim, my apologies, but I have a family member close to me who has extreme mental illnesses due to the experiences they went through when they were young. It is very hard for them to accept reality despite what everyone tries to tell them, that’s obviously due to their mental illnesses and wanting to deny the reality because it was too harsh for them. For youngwon, I believe it’s that he knows the reality and knows he can’t do anything about it no matter how hard he tries in any timeline. That fucks with him bad. Sadly, yes, it does suck that he treats hohyun shittily in this universe. It doesn’t excuse certain actions of his that he’s done, but it sure as hell explains a lot!!

but yall wtf , Ok I get that its painful and sh-t but like the seme gotta accept the fact that the uke can't remember his ass, he's stuck alone in a loop, he gotta figure a way put instead of torturing and threatening the damn poor uke
Who's with me?