The mystery behind dungeons

The explanations began slowly, and soon became huge dumps of information that I had to sift through

To start it off, the being I have been talking to this entire time called itself the Planetary Core. When I first heard this I blanked out a little, I had been talking to the core of this world this entire time?

It went further to further clarify that it was a system of laws congregated together to keep this world alive, so I could also call it this world's Planetary System. I cut it down to System for short just to make it easier when I was addressing it 

The System had gained consciousness when dungeons first began appearing on this this planet, and could only begin to act a step behind the enemies and play catch up as they began their invasion

Essence of our young world was used to awaken the first groups of hunters, paying an expensive price to grant them inherent skills that enabled them to stand against the onslaught of beasts