The supporting character's harem is very normal - Chapter 25: I found that rat

An ordinary student, a wretched peeper, a cowardly teenager with a kind heart. In a terrorist attack, he inherited the knowledge of countless elites, embarked on a path of God Jagged Tu…

He is an artist!

He is a mathematician!

He is a psychology Doctor!

He is a master of fighting!

In fact, he is a man

Taken off raw site:

A wretched, dirty young man is working during the summer when he was caught up in a mysterious explosion. After that explosion, the young man is then left with the memories and knowledge of dozens of the world’s experts.

He has changed, his heart has become cold, iron-blooded. He became a killing machine, his mind turned mechanical, calculative. Everything goes according to his plans and calculations!

In this magical, slaughterous world, a door is opened for him…

- Description from Novelupdates

Harem Dynast is the story of a princess set up in a political marriage with King Lorent, a great conqueror who is often mentioned in the Harem novels.

In 2076, technology did not bring a better life to people, but instead became a tool used by the rulers to exploit.Arthur traveled to such a cyberpunk world and accidentally obtained the check-in system.You can get a variety of technological knowledge just by signing in.Before he could do anything, he unexpectedly discovered that the original owner was already married and even had an older son.Arthur: “The freedom of marriage is sacred and inviolable. That's not my wife.”Why are you saying that my wife is Gloria and I have an older son named David?Arthur: “How can a human being abandon his family and his son? Just go with peace of mind as the original owner. After your death, your wife will be taken care of by me, so don't worry about it.”

With the revival of spiritual energy and the breakdown of the order of species, it is a difficult test whether human beings can still stand at the top of the biological chain.

(There is already an old book, The Strongest Descends in the City, you can read it.)

- Description from novelbuddy