The Great War

The Great War happened thousands of years ago, and the Blue Flame consumed the lands of Mynithrul. All from that time has been long forgotten save a few glimmers of the past here and there.
Recently, a prophecy was fortold that involved stopping the next great war by locating 6 mysterious artifacts. Our group of adventurers are one of three groups trying to fulfill this quest.
Here is what the party knows about this so far...
Thousands of years ago there was a great war and this war took over the entire plane of existence we reside on. It was prophesied that each of us would take part in this giant war. This war, thousands of years ago almost took out this entire plane of existence. Fiends came up from the ground, celestial beings appeared. The artifacts and their sacrifices gave everyone a future.