Odyssey of a Deranged Transmigrator

I, Yuuto Nanashi, was born with an avid thirst for fighting.
I battled criminals, gangs, and other lowlifes with their wide variety of weaponry.
I fought without regard for my own life, instead taking pleasure in the slaughter.
But what awaited me was nothing more than defeat.
Ultimately, I was my own worst enemy. I was diagnosed with dissociative identity disorder, the fragmentation of a person's identity.
In the days that followed, I realized that I was a mere fragment of my former self and that I was gradually losing control.
I have been imprisoned for decades within myself.
But now, I can feel it. My control... is returning...