Apocalypse: I Build A Doomsday Train - Chapter 216 - 211 Grass

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.

“How many people have you killed? How many families have you destroyed? How many towns and cities have fallen because of you!?”“I don't remember.”The villain whom the main character was destined to defeat at the end of the novel. That was who I had become.There was just one problem...“Why am I a teenager!?”“Why is there a school acceptance letter on my desk!?”

“A qualified gunner should have enough firepower coverage.”

“So my battery has a diameter of three thousand meters, which is very reasonable.”

After a grand fireworks, Chen Jiang looked at the shocked eyes of the passers-by around him and said seriously.

…

When all races were thrown into a world and started to fight, a world with the theme of survival began.

- Description from novelbuddy

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates