MC Basically

i mean that wasnt really the reason behind his like whatever depression - its matthew and how he died for him

I think that's even worse. You get depressed after your boo died and not from remorse after committing mass murder?

he isn’t real ???

Missing a few screws in the head, aren't you? Is this your first time reading or watching fiction or what? The f**k are you acting this pretentious for? War, conflict, strife are what more than half of fiction is based upon. If you are this bothered by with the fleeting backstory of a character having been a veteran soldier who fought for his people and lost friends in the war and suffers trauma as a result of it, you must be unable to stand even many shoujo mangas. I mean shoujo mangas try to be the nicest of the genres here, but even they often have plots where human conflict, even large scale military conflict plays a role. You must not read anything outside of slice of life, school life, everyday people going about their daily jobs, normal life stories, then. Or is the real problem here that characters here are soldiers named Jayden and Matthew. Had they been terrorist monsters names Jalal and Mahmud, you'd have loved them wouldn't you? This is what happens when you decide to start pretending to be a liberal or a progressive just because it's popular with the trendy and hip sections of the society. When all your moral standpoints come not from critical thinking and philosophical analysis, but from aping other clueless idiots into tokenism, this is the sham you end up with. All that you are doing is token liberalism. That lets you pat your own back with the delusion of self-righteousness that you are among the good guys, drunken with the reinforcement you keep getting from the most vocal segments of your in group. Sorry to break your little bubble but what you believe in definitely not liberalism or progressivism. I don't know what you are, far-left fringe, anarchist, islamist, ccp cultist, some right wing extremist reincarnated into a situation where normal Western world right wing shit***kery would be shooting yourself in the foot, so you are trying to blend in with the other side but can't help revealing your original dismal intellectual and moral character or just a young, immature, ignorant person who doesn't know much about the real world expect for what you get from your corner of social media, whatever you may be, you are not a progressive. The people you listen to aren't fighting for human rights, they are just fighting for their own twisted sense of vindictiveness.

Okay, fetishist gooners. Your morals have really shone through.

i think this is not the kind of work that needs to bring this topic up? unless they wanted to address it as part of mc's ptsd which could be hinted but you're reading a romance gay manhwa where the setting of a point in the plot happened to be war and it's only used to craft a background story for the mc i'm afraid this isn't the available ground for the kind of social commentary you're looking for...

wait, wait... what mass murder?? r we on the same manhwa? I don't remember anything like this.

ah you mean the war?? girl, they're soldier, what do u expect.....