looking for novels where the MC is ruthless to himself. for example, like in Otherwordly Evil Monarch chapter 5, where Jun Wuyi puts Jun Mo Xie into a lot of pain and he just acts indifferent. someone with an extreme pain tolerance i guess it could be described as. another example is like in situations when the MC can block an attack, then retaliate, he'd rather take the attack head on and also attack the enemy, injuring himself but hopefully killing the enemy in the process. and most importantly, PLEASE don't recommend novels where the mc is a pussy and afraid to kill anyone for dumb reasons like "you're just an ant, no need to kill you". seen that exact sentence like 10 times in 2 days lol basically, looking for badass mc's. on another note, i'm also looking for novels where the mc quite literally treats life like dirt. i've seen soooo many chinese novels where the MC would injure some gang of hoodlums as a show of might, and then extort them or make them his subordinates. that's fine and all, but it happens dozens of times throughout the entire novel basically each time, and that's fucking annoying. i'm looking for a similar scenario, except instead of extorting them, he just kills them, and erases the traces. to put it simply, i'm looking for an mc who kills people for things like being harassed, insulted, attempt to kill mc/mc's friends or family. basically, an mc who kills anyone for anything.
Most wuxias and xianxias have that moment where the author emphasizes the "He's so determined he doesn't even flinch from the pain blablabla" I recommend the later chapters of Hakomari. You shall see pain tolerance. There's Xian Ni too. Constant emotional pain hell yeah. Sadly, none of these two novels have MCs with a bad temper and petty personality, like the ones you're looking for.
FFF Class Trash Hero MC is hypocrite, he says he wants to go back home but what he doing is (addicted to) killing here, there and everywhere. Instead of searching for information/clues from (important??? NPC) on how to back home, he kills first and never asks anything and complains about how he can't find any clue at all. Well his only clue by his perspective alone is just kill anything that stood in his way. If you want (brainless) MC that kill anything, this is perfect for you Edit: Forgot to add, MC way of fighting is trading blow, take damage as long as he can damage enemy
Reverend Insanity is my recommendation. Though, this MC is more evil if anything and is just simply a manipulator who manipulates others to get what he wants. There are lot of deaths that are usually unprovoked. Pretty badass though since that's what your looking for.
https://www.novelupdates.com/series/way-of-the-devil/ He is not all out evil mc like fang yuan in Reverend Insanity but an Anti hero he pretty much treats everyone like dirt bcz only thing he cares about is power
Summoned Slaughterer mc is a psychopath serial murderer that just kills because he's addicted to murder (or so I got from the first few chapters)