Demon Slayer x Male Reader

Y/n L/n is the eldest in his family. He soon experiences a horrific event which leads him to training to become a Demon Slayer. However, in the far future, he experiences another horrific event which changes him whole as a person. He turns into a cold, emotionless, cruel and dark person. Will he ever revert back to his old self?

NOTE!

"I DO NOT OWN DEMON SLAYER NOR IT'S CONCEPT AND CHARACTERS. ALL CREDITS GO TO
KOYOHARU GOTOUGE AND UFOTABLE. ALSO, I DO NOT OWN SOME REGERENCES AND IMAGES I WILL PUT IN THIS STORY, ALL OF THOSE RIGHTFULLY BELONG TO THE OWNERS."