Rebirth in 1986: Unforgettable Regrets - Chapter 19 Big Sister

A wicked mother one day brought home a girl. The child was the hidden legitimate daughter of the duke, the heroine of [The Duke’s House Has Three Sons and One Daughter] Loretta. I was Melody, the villainous girl who tormented her and was condemned along with my mother. Not wanting to die like that, I decided to start treating her well now. I personally fed Loretta, put her to bed, and played with her. And then her reaction was…? “I want Melody to marry me!” Caught off guard by her endless affection, I too ended up entering the duke’s family, “I’ll stick right by Miss Melody’s side.” And there, it seems I’ve met a young lord who’s an even bigger ‘Melody fool’? All I did was be kind to survive, but why am I being loved…?!

Xiao Mengxin accidentally entered the Lixingshe Secret Service.

The only ability is to accurately identify who is the hidden Japanese.

I don’t understand anything else…

As a result, I seemed to be walking astray while walking?

- Description from novelbuddy

In a world where strength determines one’s future, William, an orphan with no extraordinary talents, faces a grim destiny—until a brutal attack leaves him clinging to life. Instead of death, he awakens to a mysterious and powerful entity lurking within his mind: the Shadow System, a game-like interface that promises him unimaginable power. But this power comes with dark secrets, and refusing it would mean his death. Forced into a pact with a voice that can hear his every thought, William must navigate a dangerous new reality where shadow abilities and celestial power collide. As he enters the prestigious military academy, his newfound abilities draw both allies and enemies, all while a deadly conspiracy brews in the shadows. With the odds stacked against him, William must unravel the mystery of the Shadow System and decide whether to embrace the darkness within—or be consumed by it. His journey from a bullied outcast to a potential god will challenge not just his survival, but his very humanity. Power always comes at a cost—will William be able to pay the price? “What am I?” William asked the system. The system’s voice echoed in his head, cold and indifferent. “You are nothing.”

Kyle woke up in a land of fantasy and magitech. The usual 'I died and woke up' bullshit, skip all that.

Except he used to be a crime lord, and society here is missing that extra kick.