Those are bad comparisons and not at all comparable to mc's situation.
"i was summoned to another world and the kingdom that summoned me tried to kill me so I destroyed them"
good point. i used my points because IRL people don't get summoned to other worlds very often, so it's difficult to build a context.
i'll build off yours, if you don't mind:
"i was summoned to another world and the kingdom that summoned me tried to kill me so I destroyed them"
"now with the monarchy gone, the people of that kingdom are not protected by any military force"
"warlords will certainly rise and war will engulf the people because this land is economically viable and has no claimant"
"there is a girl who seems to like me and she happens to be a knight for her own kingdom"
"she doesn't seem to approve what I did"
"i myself understand that revenge isn't ideal, but i'll do it anyway because feelings"
"i'm allowed to feel this way, because i was bullied before i was summoned, and i suffered"
"but i got cheat powers out of it"
the guy is emotionally ungrounded. literally suicidal. how am i supposed to sympathize with his thinking process?
if he didn't get those edgy reversal powers, his healing ability would have been low-value. the crazy princess had the correct evaluation when she booted him. for some reason, she didn't just execute the guy with her knives or magic, just teleported him to some random place.
MC got those reversal powers and power-leveled, which puts into question whether how much he really suffered. even his former classmates need to put in effort; all he did was stumble onto some conspiracy.
the Dragon Heart folks seem nice, but they're murderhobos. literally tried to actually kill MC when they first met, but they get a pass because he doesn't want to be a bully? but he was happily sadistic towards the kingdom, of course. and they killed kids who were connected to their targets as well? guess we need to look past that.
and when he gets actually bullied by others who are looking down on him, he holds himself back to the point where one of his girls steps up to defend him. it's cute, but very inconsistent.
and the kingdom that summoned him had wanted to go to war against the demons. generally indefensible unless those sacrifices are criminals - but we're going with the "war bad, kingdom bad" theme here so the sacrifices were all obviously economically viable kids and pregnant moms or something. and we're assuming the demons are all good girls like Toa.
anyways, i'm still going to read this story because there is a lot of catharsis, but i've come to the opinion that the story is pretty bad
surprising since i was quite hype for this series early on... but that was literally 7 years ago. (holy crap that's a long time ago)