More than 4,000 years ago The Shadow Lord arose from the depths of the Nether and entered the Overworld, a place he was outcasted from by fellow men. Bent by the will of his hatred and cultivation in the Nether, he had become an all powerful being.
Once in the Overworld he sought to rule over all. Of course the mortal kings at the time would not for such a threat and went to war with the Lord Of Shadows and his army. It lasted for a century until "They" appeared. "They" being the Divine Warriors. Esmund the Protector, Enki the Keeper, Irene the Matron, Menphia the Fury, and Kul'zak the Wanderer. (Shad is missing because they were fighting Shad as he is the Shadow Lord)
The Divine Warriors were able to rise against the Shadow Lord and with their powers combined, were able to destroy his physical form and send his essence back to the Nether from which he came along with his armies.
We know extensive information over Shad and Irene, research into Esmund and Enki, but nothing of Menphia and Kul'zak but their titles and appearances.