JACKAL AMONG SNAKES - Chapter 701: Everyone’s the Hero

Based on the popular Vocaloid series, by HoneyWorks, called “Kokuhoku Yokou Renshuu (Confession Rehearsal)“:

Natsuki, a third-year at Sakuragaoka High School, who holds unrequited feelings for her childhood friend, Yuu, who’s in the Film Club. However, instead of being honest about her feelings, she makes him be her confession “rehearsal” partner. Unable to say her true feelings, things start to get complicated when Miou and Akari, who are also in the Art Club, get involved! Will she ever be able to confess for real!?

Mo Yan was an illegitimate child of a rich family and was arranged by her mother to take the place of her sister in marriage to a poor man in order to fulfill the marriage contract set by the previous generation, allowing the Mo family to get their hands on that substantial dowry.

The day of marriage. Lifting the sedan chair to the door, he lightly lifted the sedan curtain, but he saw no newcomer, only a piece of paper pressed under a stone.

Looking at her flamboyant font, his thousand-year-old pupils faintly spurted out a few flames. good very good. On his perfect and impeccable face, there was a faint smile, not angry but smiling.

However, no one saw the hidden chill in that smile. That woman dared to run away from marriage, he would let her know the consequences of doing so.

- Description from novelbuddy

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.