Arifureta Shokugyou de Sekai Saikyou (WN) - Chapter 523

This is a story about a young man who sought to fight against his destiny. With the help from billions of Dragon Energies trapped on the Rising Dragon Pillar in his body, he emerged from the dark and quenched himself with the blood of ancient dragons. He fought the heaven with the Buddhist Art for the people he loved and built the Eternity Kingdom with his own hands. This is a story about the rise of the Martial Emperor who will rule both earth and heaven.

- Description from Novelupdates

All Raven ever wanted was a chance — to go to college, make friends, be loved, and live like any other girl her age. But dreams, it seemed, weren’t meant for people like her.As a scholarship student at an elite university built for the wealthy and privileged, Raven's life quickly spiraled into a nightmare. Surrounded by cruelty and entitlement, she became the perfect target. Their relentless torment stripped her of everything — her dignity, her hope, her will to live. She bore it all in silence, blaming herself even for the tragedy that tore her family apart. Despair led her to the edge of suicide, but fate had other plans.Ten years later, those same bullies, now living lavish lives of success and luxury, had long forgotten the girl they destroyed. But Raven hadn’t forgotten them — not one bit.With scars that ran deep and a heart hardened by pain, she returned — no longer the fragile girl they once broke. One by one, she would visit her tormentors, delivering her own brand of justice and making them learn that every cruel action has a consequence.Because this time, Raven isn’t the victim.She’s the reckoning!

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.