There Was No Secret Organization to Fight with the World's Darkness so I Made One (In Exasperation) - Chapter 1 part3

A lonely soul, which was placed under the care of the Lord Protector’s Manor, ended up having her lover stolen by the family’s eldest daughter and dying tragically the day before her wedding.

Leon was supposed to disappear.On Earth, he was nobody.In this new world of cultivation, reborn into a body that wasn’t even his own, he was less than that — a forgotten teacher exiled to the quiet heights of Amethyst Summit Division.No glory.No backing.No destiny.Until the Grand Return System awakened.Every resource he gives… returns a thousandfold.Every treasure he parts with… comes back stronger.Every disciple he nurtures… becomes a storm the heavens cannot ignore.While the sect mocks him as a useless master wasting potential, Leon calmly shapes a silver-haired girl born with Divine Ice Bones into something terrifying. A legend in the making. A blade pointed at fate itself.They see obscurity.Heaven sees a silent calamity rising.Leon doesn’t seek fame.He doesn’t chase thrones.But when destiny finally turns its gaze toward him…The teacher who hid in the shadows will begin rewriting the rules of the world.-----

A mysterious black card issues a different amount of money each week and Shi Lei must spend it all within a week’s time. Otherwise, he will be welcomed by the black card’s punishments.

“Spending money is really tiring.” —- Shi Lei said.

“I will set a small goal first, such as spend a hundred million……” —- Shi Lei said in self-satisfaction.

“The one thing I regret the most in life is having infinite money to burn without a choice.” —- Shi Lei finally said.

- Description from Novelupdates

A genius inventor dies and awakens in his younger self's body... but not quite. This isn't his original younger self-it's an alternate version from a reality where the supernatural is real.To make matters even more chaotic, he discovers that someone has decided he is the successor to Solomon. Now, he possesses the power to enslave devils. Armed with his intellect and newfound abilities, it's time to spark a worldwide revolution... starting from his garage!---Tags: Neutral-Evil MC (enslavement, selfish MC), Harem (of course), Inventions, Technological Progress, Sacred Gear Creation, AU DxD Universe (part of Dragon's Omniverse).This fanfic is a STEAMROLLER, with the main focus on the MC's development and his technological innovations, as well as their impact on the world. If you're looking for drama, suspense, or epic battles with no real purpose, this isn't the story for you.