Douluo Dalu 2: The True God King - Chapter 99: [DD2]:

Introduction:

Wano Country, New Tokyo.

The original soul of Higashino came here and wanted to live a quiet life without being disturbed, but the “Crime Handbook” appeared in his mind by chance. If you catch criminals and bring them to justice, you can get attribute points and random rewards.

What? Can’t do it?

According to the prisoner’s crime star rating, he can enjoy the free distribution of temporary attribute points (Buff) when he is arrested.

The criminals are getting worse and worse!

My Buff gets stronger!

Mysterious fruit of ability, powerful sword type of technique, and various abilities of different sequences and levels, all turned into magical rewards on the [Guild Handbook]…

Metropolitan Police Department: These extrajudicial lunatics are simply insane, vicious, and full of evil…! ! !

Higashinohara:

I mean…

Is there anything worse? !

…

Here is the protagonist’s self-introduction:

My name is Higashinohara, a 16-year-old high school student, unmarried, and I live in the “Academy City” New Tokyo Detective Agency in Ogawa Town, Edogawa District. The police arrested lawbreakers, and they could only go home after eight o’clock in the evening.

When I got home, I would do a handstand exercise for an hour, and taste different brands of canned coffee before going to bed, just to reminisce about some of the subtle differences, just like reminiscing about the criminals who fell in my hands.

Going to bed at eleven o’clock.

Everyone says that my work and rest are very regular and healthy.

But it’s a shame to say,

In my mind lately,

Seems like something weird happened…

- Description from novelbuddy

On the desolate barren planet of Rennes, an Asian teenager named Lin Yuan receives an admission notice for the Empire’s best military academy San Romia. So begins his life changing military school career.

【Matrix Survival Game】

All players have the same initial resources.

Each person can explore ten rooms per day, and there may be dangers and supplies in the rooms.

Do your best to survive.

…

After reading all the introductions, Li Zheng heard a voice in his ear: The daily treasure chest is being drawn, and the quality is random…

Congratulations, you have drawn a silver treasure chest and obtained a silver-quality blueprint “Normal Edition Detector”, along with several supplies.

Congratulations, you have drawn a bronze treasure chest and obtained a bronze-quality blueprint “Air Purifier”, with some supplies.

Congratulations, you have drawn the white treasure chest and obtained the platinum quality blueprint “Ion Cutting Blade”, “Intermediate Gene Culture Solution Recipe”, “TJP Type Shield Blueprint”, and a lot of materials.

…

Congratulations, you have drawn the super god-level treasure chest, and the reward……

Li Zheng looked at the brilliant treasure chest in front of him and rubbed his hands together excitedly.

- 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.