My Scheming Little Devil - Chapter 1999: Terrifying Brainstorm

A master assassin transmigrates into an interstellar era.

Other players were responsible for competing in the e-sports arena, while he was responsible for stringing up and beating up the other players.

His sword was hidden during the peak of day, and he was a gentleman who arrived in a flash of light;
As a vanguard of the eternal night, he was the variable between life and death in the world.

“As you know, the Star League’s difficulty levels are arranged in this way:
Paradise < Simple < Normal < Difficult < Nightmare < Hell < [Tyron Odin]”

- Description from Novelupdates

A weary historian dies and finds himself in a different world awakened in a life as the notorious young Duke of a southern state. His nation is weakened, his army underfed, and his neighbors revolve around his lands menacingly. No one believes his land is going to hold out until winter.But this newfound duke is no naive simpleton his enemies recollect. He carries with him the experience of centuries of war and empire, of starting and ending monarchies. From Caesar to Napoleon, from the Mongols to world wars, he has learned from each of them—and his strategy is to make history his very own arms.He organizes his smashed levies into well-trained formations, rebuilds his castles, and turns his villages into supply centers. Where others see defeat, he senses opportunity. As he triumphs, rumors spread: of a pennant red as winter snow that shall not go to ground, of a bloody duke who writes his name in gore and flame.Is he a savior who's constructing a new empire, or a tyrant who's going to bring the world to endless war?

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).