Tunnel Rat - Chapter 1: Milo

Hitoshi's life sucked and then a truck made it even worse.But death wasn't the end. He wakes up in a fantasy world as a slave, expecting more of the same bad luck. Then a maid from the super-rich Aoi family buys him to work at their huge mansion. Finally, a break, right?Wrong.Sure, the mansion is amazing. The food is great. And yeah, the Aoi family treats him way better than he expected. But something's... off. Why do they watch him so closely? Why does everyone get weird when he smiles? And why do bad things keep happening to anyone who gets too friendly with him?Hitoshi just wants to be a good servant and make everyone happy. He doesn't realize that his kind heart and helpful nature are stirring up something dangerous within the Aoi household. In this new world, his greatest talent might become his biggest problem.They say no good deed goes unpunished. In the Aoi mansion, every act of kindness pulls him deeper into a web of obsession he never saw coming.“Reincarnated into Madness: Yandere Family's Unwanted Slave” is a story about second chances, magic, and what happens when being too nice leads to some seriously creepy consequences.

Jiang Lin crossed over, he became the tragic little cannon fodder in the book.

The little cannon fodder relied on his good looks, and there was no man in capital who hadn’t been seduced by him.

He was a well-known playboy in capital, an existence that everyone despised.

Only Jiang Lin who became the cannon fodder knew what kind of life the cannon fodder lived.

The little cannon fodder’s father didn’t care, his mother died early, and his stepmother treated him harshly. There were also two stepbrothers and a “beautiful and kind-hearted” heroine sister in the family.

The first stepbrother robbed him of his position as a companion of the crown prince, and the second stepbrother robbed him of his qualification to be a student of the Imperial Academy; in the end, the heroine sister arranged him to marry a man who was about to die.

From anyone’s point of view, what Jiang Lin took was a death script. But Jiang Lin held the space in his hand, who was he afraid of?

So——
Jiang Lin made a great contribution in front of the heroine, and successfully regained the position of the eldest son of the Hou family from the hands of his two stepbrothers.

Jiang Lin successfully solved the famine and became famous all over the world as a Marquis and held the nobility.

As for the dying man Jiang Lin married, not only did his legs recover from the poison, but he also became a fearsome General, the God of War.

- Description from Novelupdates

Zavier met Cosmic Consciousness after his death. He was satisfied with every system that Cosmic Consciousness exhibited, so he wanted all of them. Surprisingly, the Cosmic Consciousness obliged him.

Zavier was reborn in an isekai full of magic and alchemy. Now, he had many routes to upgrade. Interestingly, to coordinate these systems, Cosmic Consciousness gave him the gift of being able to duplicate himself. He could clone a finite number of himself to manipulate these systems.

Magus, Alchemist, Mesmer, Tamer, Hunter, Vampire, Werewolf, Dragonknight, Necromancer.....

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By the way, it wouldn't appear NTR or some bullshit harem of courtships. MC of course will have harem but not for cliches.

Genius, antisocial, solitary, intractable , maniacal.

At the turn of every era, it is he who raises the flag of the rebel cross.

Winners take it all, losers take the fall.

He who brings order to a chaotic world, assembles talents and masterminds.

He who hides among the crowd, yet stands on the top of the world.

— The one and only, him.

- Description from Novelupdates