Dungeon King: A Lady Knight Offered by My Goblins - Chapter 584 Persuasion

The Halfling says: curiosity is power.The Dwarf says: unity is power.The Elf says: Magic is power.The Gnome says: creation is power.The Beastman says: slaughter is power.Humans say: authority is power.The Dragon always says: knowledge is power.The Gods once said: faith is power.Lynch stands on the terrace of the All-Knowing Tower, overlooking the Anriel Continent, and gently says:“I”, am power.

「Shimizu-san, you dyed your hair black.」「Ah, yes.」「Why did you dye it all of a sudden?」「Because…yesterday…」Shimizu-san, who sat next to me and had dyed her hair from blonde to black gradually lowered her voice, slightly blushed, and laid her face down on the desk.

The mysterious boy Ling Chen is saved by a little girl as he lay on the street dying. Years later, he strikes a deal to save this savior-turned sister and enters the virtual world. In a future Earth where advanced warfare has forced nations to settle issues virtually or else suffer the consequences, Ling Chen bursts into the scene and goes from unknown to legend. Yet all is not as it seems, for Ling Chen has a dark past, and there is a greater mystery at hand behind this virtual world.

To save his terminally ill little sister, Ling Chen enters the newly released virtual game world and joins a small gaming studio comprising entirely of women. From now on walking upon his path towards the pinnacle. An ancient, evil item almost forgotten by history, the “Lunar Scourge” helps forge his unsurpassable legend, and causes him to unknowingly step upon a path that is destined to be punished by the heavens, the way of the Shura.

- Description from Novelupdates

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.