MTL - I’m Always the Villain - Chapter 109 Furnace Master 14

Death is sometimes not the end!
Dead prison!
This is a magical prison. It has the ability to draw the souls of the dead people of the world, and it also enables people to gain the ability of the souls of the dead.
When Qin Song woke up, he was shocked to find that he had come to the world of One Piece, and even more surprised that he found a prison in his body…..

- Description from Uukanshu

The novel follows the story of Arnold, a porter, who accompanies warriors and superhumans inside dangerous dungeons, which are distinguished by their colours. The porters were always mistreated by the modern human civilization and even though their job was riskier than that of warriors and superhumans, their existence was never appreciated nor were they paid well. No one knows why these dungeons started to appear all over the world. The only thing they know was the dangers that would find their way into the world if they didn’t kill the monsters. But only a selected few cared about the calamity because for the rest it was all about earning money and gaining power. But nothing in this new world is constant and everything keeps changing, and this time the change would find its way towards an ordinary Porter. After stealing a scroll from the dungeon, he ran off to his home. The scroll gave him powers no one could’ve imagined to gain. But he wasn’t alone. 9 other humans had been granted similar powers... powers of the Gods! What would Arnold do with his newfound powers? Will he kill the other 8 Paladins and rule over the world which had oppressed him for years? Or will he rise against the Gods and make them repent for their crimes? Can the strength lent by the Gods be sufficient to deal with them once and for all? Would he be able to defeat his creator? Or will he join the Gods instead? Too many questions, too little time. The decisions he would make could be the end of humanity Or would an ordinary Porter, become he world’s only hope? Follow me on the journey to the power of this ordinary Porter as he becomes the Savior or the Devil.

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.