Kamigoroshi no Eiyuu to Nanatsu no Seiyaku - Chapter 55 Sword and Katana

The universe is big, and Hayden’s about to invade it. Being drafted into a demon army wasn’t on Hayden’s bucket list. But when his soul is shoved into a human soldier on the eve of a new invasion, it’s not exactly like he can appeal the decision. Surrounding Hayden are demons, excited and ready. For them, the invasion promises a feast of souls and new growth. Their target? Berlis — a sword and sorcery realm straight out of classic fantasy. Hayden’s human status puts him at the bottom of the totem pole, meant to be cannon fodder that soaks up damage and dies first. But as he plunges into the carnage, he’s learning that he was born for the madness. Readers can expect: + Grimdark action and violence + Fighting, lots of it + Multiple worlds and magic systems + Slow burn

This is an Isekai styled story, written from the point of view of the protagonist.

Discover the secret of the new, unknown world with Peter, as he sets his first steps in an empty, ruined city. Meet new people from all around the globe. Fight, laugh, and cry.

One day, when a novelist woke up from a restless sleep,he realized that he had transformed into his 12-year-old self.

Today’s headlines –
   “The Malaysian Master has broken through nine products and fought the world!”
   “The pony master is the best, sweeping Eurasian!”
   “Joe’s helper once again, suspected of nine major masters!”
   “The god of the gods is not old, the global master list re-enters the top ten!”
   “…”
   Looking at a piece of news flashing, Fang Pingxin is so tired, this script is wrong!

- Description from 69shu.org