Beast Armorer: Infinite Evolution - Chapter 21

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

What happens when a history teacher dies and becomes a prince in another world? Of course, he becomes the greatest emperor!He will use all of his family's resources for his own benefit, conquer the world, and... beautiful women! Ahem. This is a novel full of intrigue where he will get what he wants, build his own empire, and finally protect his loved ones.He is a great leader to those he cares about, but a ruthless tyrant to his enemies. In this world of magic and mystery, he will not stop until he reaches the top.But what will he have to sacrifice for victory?

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- 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.