MTL - Sell Evil - Chapter 23 Scarlet Devil

Kyoukai Senjou no Horizon chronicles the story of a futuristic civilization returned to Earth after constant warfare hindered them from traveling beyond the post-Apocalyptic Earth. At this stage, a small archipelago called the Divine States were the only hospitable land on Earth. In order to regain the space-faring technology they had lost after many years of war, they decided to recreate history with a book called the Testament as a guide.

It is the year 1648 in the Testament Era. Toori Aoi, Chancellor and Student Council President of the only academy on the airborne city-ship Musashi, faces the ten-year anniversary of the death of his childhood friend Horizon Ariadust in an accident. As he prepares to celebrate the occasion by proposing to P-01s (an automaton who looks exactly like Horizon) he discovers that his suspicion about P-01s’ appearance actually has a basis in truth; P-01s is in fact Horizon Ariadust, reborn into a robotic body. In addition to this, Horizon’s emotions had been stripped away and are now stored in eight powerful weapons called the Mortal Sin Armaments; which are now in the possession of key people in various established countries in the Divine States.

To retrieve the emotions of Horizon Ariadust, Toori Aoi along with his friends and allies begins a crusade against different obstacles as key events in history are recreated in a futuristic manner.

I am Master Siwei, and I speak for arcane arts.
This is an era of heroes and heroines.
This is an era of great changes.
In the end, it will be an arcane era opened by me.

- Description from Novelupdates

As the overweight daughter of the Sutton family, Kelsie is an eyesore to everyone. Her father can't wait to get rid of her, his wife and their daughter daughter too.The man she's supposed to marry can't stand her and looks for ways to end their engagement, all to no avail.But on the day she's to get married, she finds out she's pregnant.Her fiancé finally uses the opportunity to break off his engagement to her and her father sends her packing to her aunt in another city never to return after she refuses to remove the baby like he asked her to.Seven years later, she returns to the city to claim her position as the heiress of her mother's fortune, which her father and his wife and daughter has been living off of all these years.But not as the overweight duckling everyone expected, but as a stunning, glamorous woman.Behind her are three children: a daughter who looks exactly like her, a handsome son, and another handsome son who looks too much like the most powerful man in the city.Unexpectedly, the dimwit, her fiancé who broke off their engagement comes begging for them to get married like they were supposed to.“So what if you're stunning now and lost all that weight? Everyone knows you used to be an ugly duckling. Who knows the underhanded ways you resorted to to lose weight. Forget our past and marry me again.”The woman looked at him and snickered. “Aren't you the heir of the Baker family? Why would you marry a fatso like me?”The man huffed and said arrogantly. “Hmph! Do whatever you want. But I assure you that no one in Silicon Valley will want to marry a woman saddled with bastard children!”The triplets came up on his face and snorted in disdain. “Who's this? Where is daddy when a man like this harasses mommy?”“I told you he wasn’t worth her. Hurry up and call him quickly.”The man who was in the middle of a conference call ended it as soon as he heard the news and went straight to where she was.“Are you hitting on my wife? Bastards? Are you calling the beloved children of Jett Adler bastards?”“Eh-what? Jett Adler? The most powerful man in the city? How is that even possible!”

When I transmigrated, the protagonist was already dead.Now, I have to protect the world after the bad ending.So first things first, I became the enemy of the main heroine, who was on the brink of ending her life.“I finally understand what all those things you said really meant.”“I’m like this because of you, junior. Take responsibility.”“I can only sleep when I’m next to you.”…But for some reason, everyone is starting to act a little strange.