Very decisive about killing and revenge (no torture bullcrap) No scheming(cuz schemer mc's are usually a pushover or act like a pushover, I hate both) Doesn't get pushed around by anyone kill without mercy never get controlled by anyone takes no crap from anybody no simping No to save people/world crap instead massacre humanity Loner if possible I prefer Korean novels cuz I'm tired of simp authors from Japanese and Chinese.
Something like in a cn novel is extrairdinary david and something like that in jp is Summoned Slaughterer if i remember correctly. For extraordinary david it is not translated beyond chpt 60 yet. He does fight with humanity but he doesn't purposely fight for humanity.
sorry, I read some and dropped Summoned Slaughterer, cuz mc is simp and naive. Spoiler He killed the king but not the girl plus she threaten to kill him in the future where he doesn't do anything. And he gets stalked all the time and he doesn't do sh!t. He's pretty much a masochist to me. Novels like these are why I hate Japanese or Chinese.
i guess my memory of it is not as good as i thought. You can try Reverend Insanity. He is also pretty cold.