The Game of the Greatest Black Mage - Chapter 82

In a world where magic is forbidden and witches are hunted, Ashlynn Blackwell has hidden her mark of the witch since birth. The night of her wedding she's betrayed and her secret is exposed. Attacked by her husband and his knights, Ashlynn was abandoned and left for dead in the wilderness.Rescued by the vampire lady Nyrielle, Ashlynn is offered a choice: die as a human or embrace her power as a witch. Bound by a mystical blood pact, Ashlynn is plunged into a world of ancient magic, immortal vampires, and deadly political intrigue for the chance to find eternal love.

Genius, antisocial, solitary, intractable , maniacal.

At the turn of every era, it is he who raises the flag of the rebel cross.

Winners take it all, losers take the fall.

He who brings order to a chaotic world, assembles talents and masterminds.

He who hides among the crowd, yet stands on the top of the world.

— The one and only, him.

- Description from Novelupdates

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.