Kim Jun-Woo, the world’s first SSS rank genius hunter.
He is an incredible user of ability, but his horrible personality leads to problems with his reputation.
In the midst of his troubles, he was attacked and killed by an unidentified group.
And when he opened his eyes, he had returned to the past of 10 years ago.

Though he tries to become a hunter again and raise his rank, his skills were all sealed by the karma of his previous life.
In order for that to be released, he needs to work as a ‘Dungeon Cleaner’, which is infamous for being extremely tough in this industry?!

But this cleaner, he’s different!
Not only monsters—troublesome hunters, superiors only taking up positions after they’re hired out of nepotism, and even people who will be colleagues with him.
He’s making a complete mess to clean everything up.
The ex-hunter, who is stronger than the current hunters, and his crazy cleaning begins!

I returned from hell, after hundreds of years to save Humanity!

There is only one Magi Craft Meister in the world. After the death of the last Meister over one thousand years ago, Jin Nidou was transported to another world in order to succeed her will.After obtaining the knowledge of the Magi Craft Meister, Jin attempts to use a warp gate but it malfunctions, transporting him to an unknown place. Along with that, an automata he recently restored also uses the warp gate in order to search for her “father”. Thus, the crafting journey of the new Magi Craft Meister begins!

Dias fulfilled his parents' will to help others, and kept fighting on the battlefield to that end. Now known as the “Savior Hero” from his long wartime career, he was rewarded with a vast territory from the king. After having met the horned Kijin girl Aruna who lives there, he begins his new slow life as a lord.

One day, an ordinary high school student is transferred to another world. He raises his level in the other world, successfully defeats the Demon King, and saves the world! With his strongest status, he decided to return to his own world; however, in the world to which he returns, a new "dungeon" has appeared.

Balud Cornelius is the son of a noble of the Mauricia kingdom and inside him also dwell the souls of the stingy warring states commander Oka Sadatoshi and animal ear otaku high schooler Oka Masaharu. With these 3 souls in a single body, he can exhibit extraordinary abilities when it comes to combat or managing the domain.

A spin-off manga created by Toyotarou, and based on the arcade game Dragon Ball Heroes. It debuted in the November 2012 edition of V-Jump, the release date of which was October 20, 2012.

http://dragonball.wikia.com/wiki/Dragon_Ball_Heroes:_Victory_Mission

A young man unfortunately died in the modern era, he reincarnated in another world under the name "Eldo," which also happened to be a world similar to a VRMMO game that he used to play in his previous life. However, it's a world where he knows the "basic skills." Eldo became a level 1 adventurer, playing as a "novice," but he knows the world better than anyone, and this is because of the "data he knows." Will the reincarnation in this world make him strong?

Hayato is a young deity with a foul mouth who has always heard legends about Demons that were sealed away about 800 years ago. Follow the epic saga of several young deities, who end up having to fight demons, humans and overcome several challanges.

A remake of a web manga of the same name with new art by Cool-Kyou Shinja.

All the world's creatures lived in harmony until humanity rose to power. The flora and fauna feared for their lives and hid from the humans, leaving behind a barren world with only rocks and dirt. There are a few exceptions... Witches, exceptional women with the gift to heed plants' words, live in secret lairs full of vibrant greenery.

Tula, a powerful witch nearing the end of her life, raised her apprentice Piri in one of these sanctuaries. Piri has a lot to learn. In fact, she can't even hear the plants' voices! Naturally, she has no desire to leave her secret haven—or Tula—but situations outside of her control force her away. Where will Piri go now? Will a gift from Tula help her find her way?

Kim GiGyu awakened as a player at the age of 18. He thought his life was on the track to success, climbing 'the tower' and closing 'the gates'... But even after clearing the tutorial, he was level 1. He killed a goblin a day, and he was still level 1. Even after 5 years, he was still level 1. "Who would have thought that this kind of player would exist." No one knew.

A man was reincarnated as Van, a boy of noble birth, who grew up to become a child prodigy through hard work. But when it was discovered that he possessed "production magic," he was immediately relegated to a remote village. However, his magic, which was called useless, turned out to be truly extraordinary, capable of producing anything as long as he had the right ingredients! With the knowledge from his previous life and the overpowered magic, the small, poor village will grow to become into a great city.

Genjou is a monk on his way to Tenjiku (early East Asian name for India). Along the way, he happens to visit a house and meets an old couple. The couple has an adopted son, Taro Yamada, and they ask Genjou to rehabilitate Taro who makes trouble with his magical powers. Genjou takes Taro and travels with him to Tenjiku.

Adventurer Harten rescues the little Elven girl Auyn after her mother was killed in a goblin raid.

In another world, the Hero and the Demon King continued to oppose each other. As their great magic collided, the explosion crossed over worlds and destroyed a classroom full of high school students. The victims who died in that explosion will be reincarnated in that alternate world. Our heroine, who has the lowest standing in the class, was reincarnated into a spider. She nevertheless faces this challenge head-on with great determination, and adapts to it surprisingly quickly. This is the story of how our protagonist, who was reborn as a weak spider monster, does whatever needed to survive.

A man who was enjoying an evening drink got transferred to the body of Liam, the fifth son of a nobleman from another world.

"I spent easy days practicing the magic I had longed for, and learned not only attribute magic, but also how to summon spirits, obtain powerful familiars, and ended up mastering even the most difficult magic!"

He became an adventurer aiming for independence from his parents' house, which was scheduled to fall, and before he knew it, he became a higher-ranking aristocrat rather than one of the best magicians in the world.

Sakra, the last surviving princess of a fallen kingdom, is being hunted down for the power of Ambrosia she possesses - the ability to grant divine strength, but only to a human. With no human companion, she decides to summon one from another world in a desperate attempt to find a knight to protect her, but the man who answers her call is less than what she had hoped for.

A scout in the infamous Demon Cult, Seolhwi is on a routine patrol when his squad unexpectedly encounters a fearsome master of the Mount Hua Sect, the sworn enemies of the Demon Cult. Without warning, the Mount Hua Cult master slaughters the entire squad. As Seolhwi lies dying, lamenting years of service to the cult with nothing to show for it, he is suddenly faced with a video game prompt, asking if he would like to start again. Given the opportunity to start over and make different choices, Seolhwi vows to survive and become stronger so he can rise to the top of the Demon Cult.

Sword Magic, where a sword is manipulated using magic to freely fly in the air, cutting down enemies. Ardis is a user of this new magic art that has never been seen before throughout the entirety of the history of magic. As a mercenary, he undertakes various requests in return for remuneration, including subjugations, escorts and investigations.

On the way home from a survey request, he protects a pair of twin girls who survived their caravan being attacked by bandits, however in this world twins are considered “abominations”.

Along with the twins and a girl who accompanies him as a follower, he holds back his anger at the world which looks coldly at the twin girls due to the goddess’ intervention.

This is the story of such a swordsman called the countless swords sorcerer.

From LHtranslation :

In a certain world, there was someone who excelled in magic combat, people called him 『Sage』. Seeking the strongest combat art, he devoted himself to research every magic and combat arts in existence. And the conclusion he arrived at was very cruel, 『My body is not fit for magic combat』. Yet he didn’t give up. He sealed his own soul with a magic art, and was reborn in a far-off future. And the magic theory in the completely changed world he saw there was of unbelievably low level.