Gu Yangchun, who betrayed the Orthodox sects, became a demonic human under the Heavenly Demon.

Living as a demonic human, he led a life filled with regret. He committed countless evils not of his own accord, but under the orders of the Heavenly Demon.

In the Great Orthodox-Demon War, thanks to Wi Seol-ah, who cut down the Heavenly Demon that made even the three supremes of the Orthodox forces kneel, Gu Yangchun was taken prisoner by the Orthodox forces and suffered for his sins.

With whatever morals he had left in him, he died giving Wi Seol-ah information about the Demon Cult due to a bind the Heavenly Demon had placed on him.

Then, for some reason, Gu Yangchun regressed to when he had first met Wi Seol-ah. Realizing the regression was not a dream, Gu Yangchun decided to live a quiet life. However, bad ties from his previous life began to draw near, one by one.

Killed on the battlefield without glory to his name, Yuseong Dan receives an opportunity to grow stronger with a strange quest and level system. But each quest he’s forced to fight only seems to be getting harder and harder. Can he level up enough to avoid the same miserable ending and become the powerful hero he wishes to be?

The descendants of mankind, born in the labyrinth and raised on the milk of monsters, possessed special strength and strong bodies. When they returned to earth, mankind referred to them as dungeon babies. Among them, Kim Jinwoo was born in the deepest labyrinth.
“I never tried to become strong, I just wanted to live.”
From the lowliest excavator to the king of the labyrinth, his life story is now unfolding.

There once was a hero who was deemed the strongest on Earth.

“But he died. How would someone that we killed return?”
“Yeah. I’d love to see him try and come back.”

However, 20 years later, he actually returned!

“Why are you guys so shocked? Did you do something that you feel guilty about?”

‘These motherfuckers. I’m not going to let them be.’

From MangaHelpers:
29-year-old programmer Suzuki Ichirou finds himself transported into a fantasy RPG. Within the game, he's a 15-year-old named Satou. At first he thinks he's dreaming, but his experiences seem very real. Due to his use of a 3-time-use special power (meteor shower), he ends up wiping out an army of lizardmen and becoming very high level. He hides his level and plans to live peacefully and meet new people, though developments in the game story (like the return of a demon king) might get in his way.

All the members of my sect are abnormally strong. All my disciples turn out to be big shots, and I'll definitely become invincible in this world!

After being held in disdain and having his life put in danger, an orphan from the Demonic Cult, Cheon Yeo-Woon, has an unexpected visit from his descendant from the future who inserts a nano machine into Cheon Yeo-Woon's body, which drastically changes Cheon Yeo-Woon's life after its activation. The story of Cheon Yeo-Woon's journey of bypassing the Demonic Cult and rising to become the best martial artist has just begun.

Devoid of professional skills, unemployed Yu Damduk was forced to take a part-time job. Frustrated with his pathetic life, he vents to the gods, gets stricken by lightning and passes out.
[Hiring] God is waiting for you.
When he wakes up, he finds a status window floating before his eyes.
Since I have nothing to lose anyway, let’s go with the flow…
Jumping into God’s Part-time world to have a better life, the adventure of Yu Damduk, who became the lowest-class God in the part-time world, begins!

In the mobile gacha game infamous for its atrocious difficulty, the Master ranked 5th in the world, 'Loki', loses consciousness while raiding the Dungeon.

'What? I'm a game character now?'

After waking up, 'Loki' realizes he has turned into a Level 1, 1-Star Hero—'Han Yslat'. To return to Earth, he must lead the newbie Master and heroes and clear the 100th floor of the Dungeon!

'You messed with the wrong guy.'

This is the story of hard carrying by Master Loki who never accepts even a single defeat.

Akira Kamishiro was a very successful manga author, who was diagnosed with blood cancer one day. He regretted the way he lived, where he could only build up empty relationships. Angry at his mother for asking him to send her some money, he died in a car accident. He was given a chance to choose his new mother and reincarnate in another world.
Akira, not wanting to have a repeat of his past life, decided to choose an ordinary but safe life.. He was reincarnated as Akira, the only son of a magic store, with his previous life's memories. He had no talent for swordsmanship or magic, but he didn’t care as he was still loved by his family. At one point, he realized that he can embody various things by "drawing a picture". That's when he noticed his cheat ability...!?
This is a story of Akira who wanted to live a mediocre life in another world and his adventures to protect his peaceful place!!

The beloved characters of Mairimashita! Iruma-kun star in this Mafia-based spinoff! Young Iruma saves an injured mob boss from death... and then becomes his grandson!?

The Earth’s existence is under threat once more as Itarim, the gods of other universes, seek to fill the void left by the Absolute Being. Sung Jinwoo has no choice but to send Beru, the shadow ant king, to awaken his son’s powers and start him on the journey he once took. Suho must conquer the shadow dungeon and earn his place in the world of hunters as he navigates through a new world against a new evil looking to swallow the world whole.

Sequel to Kengan Asura. Takes place 2 years after the tournament.

This kindergarten is where the children of the world's most important figures attend; politicians, company presidents, oil tycoons, you name it! Legendary ex-assassin Rita is assigned to a secret mission to protect the children of the kindergarten from assassinations in exchange for freedom!? An Action/Comedy story about the world's "safest" kindergarten!

The ninth story arc of Jojo’s Bizarre Adventure.

O’ahu, present day. Dua Lipa is the trending musician, and COVID is still a major concern. On this island lives a 15-year-old boy named Jodio Joestar. Living with his brother and mother, he acts as a dealer for certain illegal substances. One day, his employer comes and shows him an excellent find: a Japanese person has landed in Hawaii with a diamond worth over six million dollars. Normally it would be impossible to steal, but for someone with a stand…

This is a story of a young boy and his quest to become rich.

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!

In a brutal, lawless medieval world where war and poverty reign, and twisted magic defies all reason, the captain of the guards grinds through another grueling day, pushing his battered body to the limit in a land where survival itself is a merciless test.

The golden age has dawned for treasure hunters, who raid treasure vaults all over the world in search of glory, despite the dangers.
Immeasurable wealth, fame, and power await those who prevail.

"Let's be treasure hunters!"
This promise between Krai Andrey and his friends came to a sad conclusion when young Krai realized he didn't have a treasure-hunting bone in his body.
Yet for some reason, people's expectations of Krai continued to grow—as did the danger to his life.
While his friends became greater, greedier beasts, Krai mastered the art of begging and pleading!

Witness the weal and woe of a man who just wants to retire.

The game has emerged into reality, the rules of the world have been turned upside down and humanity has entered the era of becoming players with the world set as a game stage. The only way to become a player is by leveling up to become stronger! The only way to rise to the top of the world! On the day of world fusion Lin Moyue chose to take on the sole hidden class, Necromancer. From then on, Lin Moyue would not die until his summoned creatures died out. “I sit on the throne of bones as the God of the dead and walk between life and death.” “I am a walking catastrophe!”

If you max out your level in-game, you can get heaven-defying powers in real life?!

Player Ling Ce finally obtained this reward through his hard work but ended up receiving the most useless skills. Just as he was mourning his luck, a mysterious power brought him back to three years in the past. With the experiences and memories of his previous life, how many different wonderful things can he bring to his new life?