MTL - Custom Made Demon King - Chapter 205 Doppelganger = guinea pig?

A scientist, Duan Yixin, transmigrated into another world. She possessed the body of a sixteen-year-old girl but had not inherited any of her memories. With a broken marriage engagement and no money in her hand, she only wants to earn money peacefully. It's a pity that fate always plays tricks on people.When she thought she could finally live peacefully, she discovered that this world was not as simple as she thought. The man she rescued was the notorious ruthless general, and the woman who stole her ex-fiancé was the female protagonist of this world.She looked up at the sky and asked, “God, are you kidding me?”A few years later, on their wedding night, she stared at him and said seriously, “General, I'm not your white moonlight.”The man lowered his head and whispered in her ear, “Mhm, you are not my white moonlight, you are my life.”

Wen TianHe originally thought he was a man who’s going to be a domineering chairman. But in the end, he became the man alongside the domineering chairman.

The sharp edge of a knife is difficult to cross; thus the wise man said that the path to salvation will be hard.
—Mao Mu, (Blade)

The blade of a sword must be sad for its lack in friendship. Because no matter whom it wants to give a hug, the other would be divided into two.
—Vietnamese Overbearing Chairman, Si Guan (Silence is Golden)

- Description from Novelupdates

Alex was just trying to escape his dead-end job and overbearing family. Then the System arrived, bringing with it magic, Rifts, and the chance for ordinary people to become extraordinary. Unfortunately for Alex, his stats started out as unimpressive as his old life. But when he gains the unique trait {Primordial Will}, which only allows him to put his free points into one stat, everything changes—though not necessarily for the better.Thrown into a dangerous Rift way above his pay grade, Alex quickly discovers that surviving the chaos isn't just about having powerful skills. He'll need every ounce of his Willpower and resourcefulness if he wants to make it out alive and bring home the rewards that could finally give him an edge.This series follows Alex as he begins to master the art of Mana Threads and creates a revolutionary new magic system with Spell Circles. He starts to realize that magic isn’t just a tool—it’s a path to power that few can fully grasp. But with the world’s governments struggling to contain the rising number of superhuman threats, Alex will have to navigate more than just monsters and Rifts. In a world where “might makes right,” who really calls the shots?

An otaku with a hobby of masturbating was reincarnated as the son of a great mage.

As soon as he was born in this life, he vowed with a goal of embracing women till his death.

That said, when he became 20 years old, the Demon Lord which was sealed by his ancestors revived, and now it is his role to seal it once again.

And that demon lord is sealed in a tower dungeon that is rumored to be impossible to capture.

However, by an unexpected coincidence, he had found out that the Demon Lord is also one of him, a kindred spirit from within,

so he joined her instead and filled several traps in the tower dungeon, and thus they enjoyed a s*x spree with all the women coming over!