Roses have thorns

Some describe him as a hitman, some describe him as a serial killer. One thing everyone knows is - you never get out alive.
This is a tale of a man who kills for a living. However its not his fault- he didn't want this. He doesn't have much memory of what happened, but something did. Something that made him snap. What was it? We will soon find out~
WARNING- this story contains content some readers may find disturbing/upsetting.
Currently in progress and still being edited-