MTL - Start with Batman - Chapter 324 that name

Ruins stretched across the landscape in the apocalypse after the nuclear war.

In a world fractured by conflict and haunted by shadows of the past, Kokushibo—the first Upper Moon demon—meets his end, only to awaken in a new life. Reincarnated as Crimson, a child born into a different family, he carries the memories of a past he cannot escape. Burdened by centuries of guilt yet indifferent to the present, he resigns himself to duty—until an unexpected bond with his newfound family begins to thaw his hardened heart. As he struggles between the weight of his past and the weight of the new life, Crimson must decide whether he will remain shackled to his former sins or embrace the possibility of peace.

Alexander Blackwell has always been a man of taste, charm, and relentless ambition—traits he inherited alongside the world’s largest fortune. When his legendary father, a trillionaire who built an empire from nothing, passes away, Alexander wakes up to a reality most could only dream of: unlimited power, endless wealth, and a blank canvas to shape his legacy.But Alexander isn’t content with simply inheriting the Blackwell name; he’s determined to redefine it. From purchasing private islands to creating monuments of vanity, hosting the most exclusive events, and launching ventures that blur the line between brilliance and indulgence, he sets out to make himself unforgettable.To Alexander, ambition and excess go hand in hand. After all, what’s the point of having everything if you’re not building something bigger? What’s the point of having it all if you aren’t living like it?Disclaimer:This work is a work of fiction. Any resemblance to real persons, living or dead, or actual events is purely coincidental. All trademarks, brand names, and other proprietary rights mentioned or depicted are the property of their respective owners and are used for illustrative purposes only. This work is not affiliated with or endorsed by any brand, company, or individual mentioned. All rights reserved.

Sergeant Xia Yao, born into a wealthy and renown ancestry, is a playboy who has turned over a new leaf. Yuan Zong is an ex soldier from the special forces who opened a bodyguard training company after being discharged.

When Yuan Ru, Yuan Zong’s sister fell for Xia Yao’s charms, but could not break down his erected barriers, she came to Yuan Zong for assistance. Little did she know, the moment Yuan Zong saw Xia Yao, this ex-special force knew no other person would ever catch his eye.

And so begins the battle between brother and sister for the most coveted price – Xia Yao’s heart.

- Description from Novelupdates