The First Blood

Two beings transcending reality came into conflict, neither could ever kill the other truly so it came down to a single action, One of these beings attacked its foe with the curse of Blood, Bone, and Flesh sealing it to the world with a life and form. Such limitations drove the loser mad with mortality, but it was forever barred from challenging the victor ever again so it instead turned its anger to the mortal life all around it. It became a God easily, demanding life to power it and became the first Blood Mage. So it dominated for centuries, blotted the sun and brought on the Age of Darkness.
 
It was only after Rykel, the God of the Sun, tore down this monsters idols and temples and threw the beast into a sealed Tomb hidden deep within the earth. The beast could neither die nor reach the level of its previous life, so it lived forever trapped, but from its nightmares and rage were born horrid Nightwalkers that continued to plague mortal life. 

It spawned the horrid Dust Lords, (my personal spin on Vampires)