Overpowered Villain Returnee in the Apocalypse - System is for Losers - Chapter 24: If You Don’t Have Someone to Fight...

Jiang Pengji got something called the Court Intrigue Stream System.
System: “Your goal is to become the most prestigious woman in the kingdom (the Queen)!”
Jiang Pengji: “Okay, System. No problem!”
Years later, she met the target by becoming the most prestigious woman (the Empress).
Jiang Pengji: “Well done, no?”

- 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.

A teenager finds himself in the Marvel World with the Dragon Balls, and has to find a way to survive!

Shenron: “Say your wish! Any wish can be granted, but you only get one…”

Teenager: “Any wish could be granted?”

Shenron: “Of course!”

“Great!”

Teenager: “Shenron, please get me out of the Marvel World; return me to my original world!”

Shenron: “I’m sorry, I can’t do that…”

“….”

Teenager: “What? What were you bragging about then, saying you can grant any wish?”

Shenron: “Your body is from this world, therefore….”

“….”

Teenager: “Okay, then give me the power of a Super Saiyan! I want be able to beat Thor and Hulk, surpass Captain America and Iron Man!”

Shenron: “I’m sorry, I can’t do that…”

Teenager: “Worthless dragon! What can you do?”

Shenron: “I can…”

- Description from Novelupdates