My Dem/Vamp. system

The human Race is at war with the unknown and they need help more than anything then god started gifted people with abilities.
At same time the Dungeon started to manifest but Human kind were not going to backdown without a fight.
After 20 years war with the unknown world is came to peace but they don't know how long this peace going to be.
Ammie have lost everything in this war his parents left a Ring with Dark Red gem in it and nothing else.

He was Granted System which turn his life upside down and now he have to find why this war is happening what the unknow want from and why the dungeon is manifesting.
Will he be able to get bottom of this??