MTL - Pretend To Be a Good Person In the World of Conan - ~ You know too much

Worlds overlapped, and Alien Species descended.Strange entities emerged one after another, as the shadow of evil spread wildly.The calm of life was shattered, and Zhang Xiaoman, inside a fish's stomach, accidentally consumed a system named “World-saving Plan”.From then on, he became the only person among all humans with Extraordinary Power.…Inventing an ancient oath, he established a unique methodology, Cultivated Dark Energy, founded an organization, took Control of the Transcendent, and resisted invasions.Well, this is actually the story of how a Big Con Man bluffed his way into saving the entire world.PS: Contains elements of the behind-the-scenes, Cthulhu mythos.

The most feared Assassin in the world died because of vengeance.

I, Seiren Shikino grew up in an orphanage. On the day of my high school graduation, I somehow got transported to another world, and turned into a girl as well. ……Eh, this isn’t my original world and gender, right!? It seems that I’m now Seiren, the daughter of a noble from another world. This is a light hearted story about family and romance.

He died on the wedding of the girl he had a crush on, after a long and successful career. After convincing Yama to send him back to the world, he decides to fix the areas in which his life went wrong. Realizing the lack of love and romance in his past life, he sets out to conquer the hearts of various women.

- Description from Novelupdates