Fear of the Dark [COMPLETED]

Overview:
Can Rin save humanity?

In the near future, a portal to [void] will appear somewhere in the world.
Monsters crawl out of the portal and rampage.
Humans create villages around [void] to keep them safe.
Humans then use the monster’s gene [red eye] to create a cyborg to thwart the monster’s attack.
Twenty years later, the dormant [void] suddenly began to expand again.
The main character, Rin, needs to investigate the cause behind her and save humanity from extinction.
In the near future, a portal to [void] has opened somewhere in the world.
Monsters are crawling out of the portal and rampaging.
Humans have built [villages] around the radius of [void] to keep them safe.
Humans also used the monster’s gene, the [red eye], to create cyborgs and thwart monster attacks.
And 20 years have passed. The dormant [void] suddenly started to expand again.
Our protagonist, Rin, needs to investigate the reasons behind her and save humanity from extinction.​