Recommendations Wants a despaired MC ( cold , hearltess , dangerous , tragic past )

Hello guys I'm looking for a MC that naive in the start or even an idiot but suffered something that has made him despaired and becomes a cold blooded , headless , dangerous , person ....

Plot can also be like he got them recruited by an evil organization and blah blah blah!!!

CN is not compulsory*

R18 MUST BE INCLUDED*

 

It's not shown when he changed but Reverend Insanity sorta fulfills your condition.
Other than that, Renegade Immortal works too.
Rising of the Shield Hero for a good portion of it was like that too.
And then there are the multitude of the abandoned in a dungeon and left to die tropes like Arifureta, though this one he didn't really become truly cold blooded.

 

A Sorcerer’s Journey
Age of Adepts

 

W

Well I hve read all of these and these are very good ones too but I want something where the past of MC gets attention too... Like someone heard bout his past and got emotional and helped him that lead to him becoming a bigshot (evil one)

 

• Main Character Hides His Strength
  
• Nidome no Yuusha
  
• The Charm of Soul Pets
  
• The King of the Battlefield
  
• Reverend Insanity
  
• Pursuit of the Truth
  
• The Dungeon Seeker
  
• Plague Doctor
  
• The Void Wolf
• Would You Please Become the Demon Lord?
• The Whisper of the Nightingale
• The Great Demon System
• Supreme Magus
• Stunning Edge
  
• Demoness’s Art of Vengeance
  
• You’ve Got The Wrong House, Villain
  
• Genocide Online ~Playtime Diary of an Evil Young Girl~