City of Sin (Yanyu Jiangnan) - Vol 9 Chapter 70

Madeline Celeste d'Aumont is the first daughter of Duke Aumont and Duchess Louise-Marie d'Aumont who has been engaged to the Second Prince of Pays Des Abrutis since she was a child. The Second Prince decided to marry a woman closer to his own age and broke off the engagement to Madeline who was left with a broken heart and a reputation as being an unwanted woman even before she was an adult. The Duke decided to help his daughter regain her confidence and reputation by sending her to the Academy de L'échec.

Ito Aoi was the son of a Kendo master who ran a dojo in downtown Tokyo. One day while crossing the street to get some Yakitori, Aoi was hit by a delivery truck and woke up as the trash first son of Duke Montfort, Guy de Montfort. Duke Montfort also sent his son to Academy de L'échec only Aoi instantly recognized that he was now living in the world of an Otome Game that his sister loved to play and talk about all the time. Aoi recognizes that Madeline is the villain from the game. Aoi also recalled his sister saying that Madeline was terrible in the game, but is she really?

In each world, there would be the ultimate blackened female lead called Lin Xia, and each of them would’ve drowned in the light of their first love, aka the moonlight. Unsurprisingly, all of these moonlights were beautiful, attracting the love and adoration of Lin Xia, but in each and every world, the moonlight would eventually leave in the end, ultimately causing the blackening of Lin Xia’s fragile heart.

Years later, when the blackened Lin Xia finally fell for another woman, the special memories of the moonlight which was buried deep within her blackened heart began to fade, replaced by the light of the true soulmate.

And when the memories of the moonlight faded to almost nothing, the moonlight returned abruptly, only to be rejected by the moved-on Lin Xia. Filled with a crazed sense of jealousy, the moonlight began to destroy the new couples’ lives, only to be hated entirely and finally, crushed cruelly by the angered female lead.

And this is where the story begins, as a world-hopper, Ye SangSang would complete her missions in these worlds.

- Description from Novelupdates

Due to an unexpected turn of events, Xia Fei consumed a Super Gene Optimization Fluid that bore no brand, expiry date, instructions or stated its place of origin.
Our story begins here…

At the beginning of the 21st century, twelve reincarnations shattered the void and returned to their hometown.

They preach the world and reopen the space of reincarnation.

Then……

“The Republic of East Asia announced that it will fully implement a five-year spell casting and twelve-year simulation mage training policy.”

“The Republic of East Asia has announced a new change in the marriage law, making it legal to marry someone you call upon after meeting the adulthood conditions of your respective race.”

“The Republic of East Asia announced that the East China Military Region No. 1 Mobile Armor Brigade was established, and the special humanoid mecha “Gundam” officially joined the campaign.”

“Congratulations from the United Kingdom on this, the upper hero Arturia Pendragon will visit Shanghai next month”

“In the far east of Japan, the ignition of the wave engine failed, or seek energy assistance from the East Asian Republic.”

“Space cracks have been discovered in the Chernobyl region, alien creatures have ravaged the Chernobyl region, and the Russian Defense Forces have entered the battle.”

Four years after twelve reincarnators changed the world, Li Ping entered his own battlefield for the first time.

PS: Although the introduction is like this… but in fact it is written about two thorns + machine battle + movie + mythical stew…

- Description from novelbuddy