Toaru Majutsu no Index: New Testament - Volume 1, Chapter 1: A Peaceful Academy City Without "Him". City.

Prince Kaelen Verath is a royal disgrace—a “good-for-nothing” heir who drowns his shame in wine and brothels.But when traitors slaughter his family and reduce his kingdom to ashes, Kaelen’s desperate pact with the Voidwell, an ancient power that consumes souls, grants him unimaginable strength… and hollows him into a monster.Death offers no escape.He becomes a regressed prince who once watched his kingdom and family burn, only to fail in avenging them without losing himself.Now given a second chance, he refuses to settle for mere survival or revenge—this time, he wants everything.Every empire, every kingdom… all under his control.But with every soul he consumes and every ounce of power he gains, a piece of his humanity is lost.How will he balance power and control?Can he become a supreme ruler and still remain himself?What is the cost of Absolute Sovereignty?————Send Powerstones for a guaranteed mass release!

The scum’s or villain’s long road of transformation was tentatively set to the world:
The abandonment of the educated youth’s wife (Completed)
The hidden marriage of the scum film emperor (Completed)
The best brother in the world (Completed)
The Phoenix male who destroy the bridge after crossing the river (Completed)
The treasonous general (Completed)
I’m an honest man (Completed)
To become the top scorer in the School of Agriculture (Completed)
The soft rice man’s self-cultivation (Completed)
The whole world is reborn (Completed)
I want to survive on a desert island (Completed)
The stallion male who has seized the opportunity (Completed)
The perverted self-salvation (Completed)
The spring of the loafer (Completed)
The misplaced life (Completed)
The miser career (Completed)
The ghost is out of feeling (Completed)
The Queen’s favorite husband (Completed)
The vicious girl with her godfather (Completed)
I want to be a good person (Completed)
I does not tear up the family (Completed)
The perverted common plant (Completed)
The Mary Sue’s men (Completed)
Every time I was reborn, someone wants to kill me (Completed)
The old people’s counterattack path (Completed)
The global evolution (Completed)
When I became a net red (Completed)
For you, good person (Completed)
His heart had white moonlight (Completed)

- Description from Novelupdates

Chang’an, Jan. 14th of lunar month, Tianbao Year 3 (744AD), Tang Dynasty.

For residents of Imperial City, what awaits them when the city enjoys its dazzling brilliance and joy of the Lantern Festival is an unexpected catastrophe that’ll destroy all. Tujue (a nationality in the north of ancient China), Wolfpack, kidnapping, assassination, rampant flames that scorch all…start the gear for the doom of and the Longest Day in Chang’an.

And the only hope lies in a one-eyed convict sentenced to death and the fleeting Twelve Hours…Will Chang’an, the city of prosperity, survive the longest day ever or will it burn…

At the Edge of the Void…A soft blue light hums, pulsing with energy, its robotic voice ringing with purpose.> “Do you accept me, System 0404, the Harem-Building System?”A young man in his twenties, eyes shining with excitement, eagerly responds:> “YES!”The blue light flares—The universe shifts—The binding process begins—DING!> [System Successfully Bound to…]…Daphne Han???????***System: “If you’re going to RUIN the harem-building mission, I’m not helping you!”Daphne: “Okay, I’ll just win without you.”System: “…Wait, what?”***World one:Male Lead: “Why are my offers disappearing?!”Daphne: “Oh? Maybe you just weren’t talented enough.”System: “YOU CAN’T JUST DELETE THE PROTAGONIST!”Actress #1: “Wait, I actually love acting, not this forced romance subplot?”Actress #2: “Oh wow, working under Daphne is way better than chasing ML’s validation.”Male Lead: “WHERE DID MY HAREM GO?!”System: “DON'T RUIN THE PLOT!”Villainess: “What do you want in return for everything?”Daphne: “You.”System: “NOOOO, SHE’S SUPPOSED TO BE HIS FINAL LOVE INTEREST!”World two:Emperor: “You were supposed to compete for my favor!”Daphne: “Nah. I’m the one with favor now.”Heroine: “Can I join your court instead?”System: “THAT'S NOT HOW HAREM DRAMAS WORK!”***CEO: “I was supposed to be her fate!”Demon Lord: “SHE WAS SUPPOSED TO REDEEM ME!”Imperial Prince: “What do you MEAN she’s not interested in me anymore?!”System: “THIS IS NOT HOW THESE STORIES WORK.”