Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 6 Chapter 15

She, the world's chief doctor of the 21st century, the legendary overlord of the medical world, was killed and her soul transmigrated…She, the useless miss of the Windcloud Empire, was ugly, silly, and obsessed! She died in her own sister and fiancé's hands…When she reopened her eyes again, she had the soul of the strong but the body of the weak…When she became her, her fate would be rewritten and a miracle would appear…This was a story of a two-faced person meeting another two-faced person. With pure hearts, they would end up together.

In the vast Marvel universe, where superpower was still slowly growing in its infancy, several peerless superheroes tried to find their path in The Marvel Universe. A young adult named Ron from modern Earth unwittingly stumbles into such a world and begins his journey with an unknown power. This is a magnificent yet unknown true marvel world! This is the story of a normal young adult and his adventures!

- Description from Novelupdates

It is an era of artificial superintelligences, interstellar travel, gene medicine, and virtual reality worlds. Far into Earth’s future, 15-year-old Gu Ding is a student of Cerulean Military Academy by day, and tavern waiter by night. His ambition: Become the space pirate with the highest bounty offered by the Universal Federation Government. With the help of Neptune, a neonate super-intelligence, Gu Ding finds himself thrust into a galaxy of shadowy organizations, political underdealings, and otherworldly forces that lie beyond human comprehension…

The ordinary world is not ordinary, ordinary people are not ordinary, and safe places are not safe.

This is a story of a passer-by male protagonist who is entangled by various girls with strange hobbies or even non-human beings while surviving in the cracks and opening a harem.

- Description from novelbuddy