First it's a fiction story..you dont rlly need to took it seriously..
second..this kind of setting is rare to isekai system story..where have u even see a hero become a villain due to the system faulty for not giving benefits to them after they returned to their own world? And basically the after story of most typical isekai story ending?..its doesn't matter if in reality his doing is wrong..this is unique story..the ending better be unique also for the entertainment
I actually would be left satisfied with him destroying the world or atkeast him getting a justifiable end cause its legitimately what he deserves. There's never a why it's just how there's 8 billion people in the world not everyone is gonna know him but if your mind is broken enough then yes you won't care anymore, he was literally gonna get beat up for a guy bumping into him. Plus this is a manhwa uts never that serious talking bout lock in

still dont understand how some people WANT the sword hero to win like huh? you seriously think him killing everybody (men women children everything) and destroying the entire world is a good ending and you'll be left satisfied? he has a sad backstory, sure i can agree his life after he returned sucked balls the people he fought so hard to come back to all hated and abandoned him but why does the whole world need to be punished? i said it back then I'll say it again. hes just throwing a tantrum even the manhwa says it and look i can understand sympathizing with him hell i understand why he's doing what he's doing but AGREEING? SIDING with his genocide? guys lets lock in and start using our heads pls