Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 4 - 4-7. Satou's Secret

Chu Xuan transmigrated to a fantasy world and became the young master of a powerful family. He was rebuked for misbehaving just because he sneezed during a banquet. As punishment, he was banished from the ancestral mansion and was relocated to a remote residence.

He did not mind the punishment at all. He just needed a spot that could allow him to be a shut-in. With the system that would allow him to grow stronger by being a shut-in, the longer he stayed indoors, the more powerful he became.

After being a shut-in for a day, he was rewarded with the Indestructible Body Technique.

After being a shut-in for a month, he was rewarded with the Immovable Mountain Technique.

After being a shut-in for a year, he was rewarded with the Yuxu Celestial Scripture and 100 years of cultivation.

After being a shut-in for 10 years, he was rewarded with the Chaotic Indestructible Body and the Bell of Chaos.

…

Chu Xuan declared, “No one can make me leave my home. I like being a shut-in!”

Zend Wolfled, a fallen nobleman known to the world as the most hated man in the world. And the main villain in a famous romantic fantasy novel.He was feared and hated because of what Zend had done so far without knowing what caused Zend to do these things.Zend has a secret that the world doesn't know that he is a Reincarnator and Tranmigrator. Zend knows that he is a villain character from a romantic fantasy novel, but he lives on his own terms.In the end, Zend only lived as a name labeled a villain by the whole world.Until the day comes, Zend was the last human to survive the appearance of The Evil One.The Evil One and The Angel saw the potential in Zend and sent Zend back to time Zend younger, second change-In this life, Zend will be the hero and villain of this romantic novel once again. Zend will engage with this entire world. Meet Transmigration, Reincarnated, 7 Sins, 12 Color, 6 disaster and Apostle.Zend Wolfled regret, hatred, anger, sadness and revenge will begin once again...

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

In a world ruled by the Heavens, cultivators must form a Heaven’s Pact to gain power—except Lin Feng. Born with a Broken Soul, he is cast out as cursed and powerless.Everything changes when he discovers an ancient altar and meets the Usurper, who grants him the System—a forbidden technique that allows him to steal fragments of others’ Heaven’s Pacts.With each stolen fragment, he edges closer to uncovering the truth of this world, but defying the Heavens brings trials and tribulations.Will he topple the very Heavens themselves, or will he be crushed under their divine wrath?