City of Sin - Book 9, Chapter 120

After spending his sixth year at Hogwarts a century ago, Harry finds himself back in the cupboard under the stairs in 1991, once again receiving his Hogwarts acceptance letter.“You’re telling me my parents were killed by a dark wizard?” Harry asked. “Who is this dark wizard? Why are you all so afraid of him that you won’t even say his name?”“It’s Vol—,” Hagrid began cautiously. “Well, we call him Voldemort, because he personally killed hundreds of people.”Harry nodded nonchalantly.“And what happened the next day?”Hagrid: “Uh?”--

The story is about a man whose compulsive tendencies make it impossible for him to keep a job, and a young girl who skips school and loves insects. The two meet, come to support each other in reintegrating into society, and fall in love. There’s a problem, however: namely, the parasites in their heads.

I am the sword.

Killing a man amidst a thousand miles, no one dares take ten steps.
Killing a man amidst a thousand miles, no one can take ten steps.
Killing a man amidst a thousand miles, ten steps? Not possible!

I am the sword, the sword is me,
On the path towards heaven, each shall wield their own.

- Description from Novelupdates

After causing a tech disaster in the real world, genius shut-in Rin Katsuro is sentenced by the gods and banished to Ereborn—a realm ruled by chaos, where ancient scripts control magic and dungeons feed on trauma.He wakes up in the body of a legendary war criminal—the Demon King's General—and is mistaken for the adoptive father of a demon princess.Armed with unstable “Error Magic” that lets him rewrite reality like code, Rin doesn’t want to be a hero... but when angels declare war on the demon races, and his daughter calls him “Papa,” he might just rewrite fate itself.This is the story of a broken man with nothing left to live for—until an entire world starts calling him Dad, Demon, and Destiny.