From publisher blurb:
Opposing the seraphim are the powers of the Darkness, former servants of the Most High who rebelled against his rule, as depicted in Christian Scripture and apocrypha. After their defeat they were cast into Hell. Over the eons since then other servants of the Most High fell from grace, bolstering their infernal ranks.
Dragons are former major seraphs who participated in the original Fall, defying the Most High and creating war in Heaven. They are the power behind all the Darkness, both literally and figuratively. Even chained and imprisoned in the depths of the Earth, they command their followers, working to free themselves at any cost.
Rogue Mage Creatures of Darkness Vol 4: Dragons details a general dragon, and provides specific information on the dragons Azazel (the Aqua Dragon) and Semjaza (the Black Dragon).