MMORPG: Rebirth of the Legendary Guardian - Chapter 24: Jubilant March

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

Qiao Nan: Crap! I am your biological daughter, yet I am treated as if I was picked up from the streets. In fact, you treat me worse than that!

Mother Qiao: Qiao Nan, you are not as pretty or smart as your elder sister. You are not as blessed as her. You have no right to study, marry, or to have your happiness!

Qiao Nan: Why am I not allowed to study, marry, or to seek my happiness? I will find a man right now and marry him!

Qiao Nan is dumbstruck upon discovering that the man right beside her is a powerful figure in the quad—the person who has the most promising prospects to be the future Chief.

Qiao Nan stares at the well-built man in front of her. He has firm abs and cold, chilling eyes. She swallows the lump in her throat as she says her greetings, “Good Morning, Chief!”

- Description from Novelupdates

In the northern part of the world, a long-standing battle between various races and the demon race has finally reached its end. The Demon Lord, a figure with black hair, red eyes, rules from her obsidian palace, having repeatedly defeated the Goddess, the strongest being in the world. However, she refrains from killing her, knowing she will only be reborn to lead another attack.As the goddess kneels before her, badly injured and helpless, the sounds of explosions echo outside, signaling the imminent victory of the alliance. Despite her immense power, the demon lord acknowledges the demon's overall weakness compared to humans and the Alliance. The development of fighting energy and mana has allowed ordinary humans to fight demons, leading to the demon army's defeat.Aware of the Alliance's intent to enslave the abyssal demon, the Demon Lord decides to cast a forbidden spell that will cost her life. As the Alliance forces storm the palace, they hesitate upon sensing the spell's energy. The Demon Lord vows to resist and be reborn to save her people.Meanwhile, the goddess reflects on the demon lord's past treatment of her and acknowledges her respect and dedication to her people. As the demon lord prepares to cast the spell, the goddess asks if she can abandon her plan and live freely. However, demon lords are duty-bound to restore the demon race's glory and protect her people.Understanding the demon lord's resolve, the goddess readies her sword, intending to clash with the demo lord's forbidden spell. The resulting explosion creates a mushroom cloud, marking the end of the conflict and the start of a new era. The Demon Lord and the Goddess become historical figures, their stories occasionally told.

It’s a story about a man who got transported into a novel and possessed a slum boy. He met a noble girl and served her as a butler for 13 Years. Now the girl has already fallen from her noble life and lives in an abandoned mansion with paralyzed legs. Why did she become like that? Of course because she is the villainess in the novel.