Naruto: The Outsider's Resolve - Chapter 4.5 (105):

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates

When a glorious old civilization was toppled overnight, a strange purple moon rose and thus began the Purple Moon Era.

Damn it! What kind of ecosystem was this? The evolution was messy. Even rabbit bites and plants were not to be messed with. How can one survive all this? Evolve into a Purple Moon Warrior? What did this have to do with the Purple Moon?

What kind of map was this? The Safety Sector? The Floating Domain? The Darkness Port? The Storm Voyage? The True Capital?

The Horror Lullaby List? The resurrection of the Underground Tribe and the prospering Underground City? The Chaos Black Market that suffused the world? The Bloody Road?

More importantly, one could end up in a bloody slaughter when dreaming and enter the Dream Domain? Fine, this damned era!

- Description from Novelupdates

Kain, a young teenager, accidentally lost in a Dungeon and awakened a special system. A system that allows him to continuously return to level 0, using his level to add and increase his skill points. From there, Kain began his journey to find the truth of this world, and when he took off that mask, what he saw was...

An ordinary student accidentally traveled into an other universe and became the king of a small kingdom. He had gotten a “Cheating Code” of life and was able to complete something extraordinary. This is the story about a king that was able to conquer continents and leave behind him an ultimate legend that will be recited between every generation to come.