I Have the Alchemy Emperor in My Head - Chapter 2290 - : One Death, One Subjugation

In a world where power defines worth and survival is a privilege earned through strength, Ronan was just another broken soul—bullied, beaten, and forgotten.Until he snapped.[System Activated][You have acquired an S-Class Ability: Starflame][Extreme rage and deep-seated hatred detected][You have obtained the unique skill: Devil’s Covenant]Once a victim, Ronan begins to rise—with a system by his side that grants him power through every action.When he cooks:[Skill Acquired: Home Cook]When he reads:[Skill Acquired: Speed Reading]When he fights:[Skill Acquired: Vital Strike]And these skills?They evolve.[Skill Devil's Covenant has upgraded into Devil's Divine Judgement][Skill Speed Reading has upgraded into Hyper Comprehension][Skill Energy Slash has upgraded into Demonic Slash]Every moment, every breath, every choice brings him closer to power.A hero, or a villain?He stands among them.

Down and out of luck, Yuki was. She was fired from her job and needed to find money to pay rent for her low income housing. The only saving grace was a news report she saw. Soul Fusion Online: a vrmmo taking the world by storm. A place where players can turn in game money into cash in the real world. A living world where even the NPCs are as real as anyone you would meet on the city streets. A game with cultivation and leveling mixed together.

After creating a male character to play the game with, Yuki begins her journey on her path to becoming a legendary figure in the gaming world. Meeting new friends along her journey, she slowly begins to come out of her shell and loner life, both in game and real life.

Doomsday comes, and human beings enter the heavenly world.
Ten years later, Yang Chen, who was betrayed tragically, returned strongly with the Tianyu bug. In this life, he vowed to make the betrayal pay the price. He has a powerful bug bonus, just like an open hang. Frightened to hear…

- Description from novelbuddy

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.