D.E.M.O.N.S: Getting Summoned Weekly isn't so Bad - Chapter 304: The Review Process

One day a young man found a mysterious door in his grand father house and that door transported him to Tensura....welcome to the new world...all the credit for the characters and main story goes to the owners, this is just a fanfic none of the characters or the storyline belongs to me...Tensura won't be live until later in the chapters, so if you in a rush, you can quick rocks...

Liam Sera Banfield is a reincarnator.

After an unexpected romantic encounter with the newly appointed beautiful county magistrate, Xu Qianli, who originally faced setbacks in both career and love, begins to turn his fate around.He rises steadily, gaining success in politics.“Power, wealth, and beauty are all within my grasp!”

Through a mysterious portal, Chen Jin arrived at this strange place – a post-apocalyptic world where civilization had been destroyed.

Consequently, he found –

A piece of metal scrap
A robot trash collector
A battleground
A city
A ton and more of gold
A copy of high-tech documents
A…
In short, Chen Jin found a planet.

- Description from Novelupdates