Jitsu wa Ore, Saikyou deshita? ~ Tensei Chokugo wa Donzoko Sutāto, Demo Ban'nō Mahō de Gyakuten Jinsei o Jōshō-chū! - Chapter 22.1 - Dragon-sensei is Quiet (1)

For his sake, she was willing to abandon her career as the best actress and be his wife. With her own network, money and unscrupulous methods, she helped him rise to the top of the world. He, on the other hand, held another woman in his embrace and kicked her away with no mercy. It turned out that all he ever wanted was her rare blood type, her six-month-old child’s cord blood. It was her life… When she opened her eyes again, she returned to her 20-year-old self. Time repeated and her life rewound. In this life, she would live well.

Jiang Pengji got something called the Court Intrigue Stream System.
System: “Your goal is to become the most prestigious woman in the kingdom (the Queen)!”
Jiang Pengji: “Okay, System. No problem!”
Years later, she met the target by becoming the most prestigious woman (the Empress).
Jiang Pengji: “Well done, no?”

- Description from Novelupdates

The royal bastard of House Vasquer, Argrave, changed after his stay studying magic at the Tower of the Gray Owl.

The sickly man's awkward posture and cruel behavior have been replaced with a neat dignity and acerbic wit.

Though once listless, he now strives towards his goals with a life-or-death tenacity.

Most come away thinking he seems to know too many details about too much. Few can claim to know his motives or his goals.

Yet behind that confident appearance, the primary contributor for an open-world RPG's wiki battles existential dread and things far beyond his ken as he struggles to adapt to a grim, gothic fantasy world mirroring his favorite game.

The prospect of fighting against a world-ending calamity loses all of its appeal when it transitions from entertainment to reality.

Argrave is spurred towards unwanted heroism to preserve his life as he struggles desperately to keep this sinking ship afloat.

The story is about a a hitman, Who dies because of his own recklessness and transmigrates into a game he used to play after his retirement as a hitman.I'm not gonna spoil any further, but i might answer few of your questions.Is MC overpowered?Nope, he'll become strong over time and all battle he'll fight will be because of his effort and techniques.Is there magic and adventure?Yes! It have both magic like normal isekai with adventure and fighting with monsters and many other things. There are other important things like “Essence Stone” But let's talk about it in the chapters.There will be harem?Not really, He will be in contact with many beautiful female and males but one waifu but i haven't decided yet.All i can say is, give it a try, I'll try my best to make it worth your time.