Sansan

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 Race 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! 

Dark Moon Era

Tang Ling knew from the information library of the First Reserved Camp that sleep was important to the human body.

There were two types of sleep: rapid eye movement sleep (REM) and slow-wave sleep (SWS).

During REM sleep, the eyes of the sleeper would move rapidly and their dreams tended to be more vivid. REM sleep could arrange the memories during the day and the brain would be restarted, so it was great for recovering one's spirit.

During slow-wave sleep, the brain would produce slow waves with low frequency. It was considered important for memory consolidation, and it was great for the body to recover and revitalize.

When the two stages of sleep combined, it would form a full sleep cycle which lasted for 90 to 110 minutes.

A normal man required four to five sleep cycles, which was the equivalent to seven to eight hours, so that the body and spirit could be maintained at its peak.

Move Around Freely Part 2