A Seraph is a god-like figure each with their own values and goals. There is a pantheon of Seraphs known as "The Eight", or simply refer'd to as "The Seraphs".
The Eight aren't the only gods that exist, or that have ever existed. In fact, there were many others who arose in the distant past - some survived to the present, some did not. There are varied tales explaining why they were kept out of the pantheon of the Seraphs, their worship limited to small cults forced to dwell in the shadows. Many of these exiled gods are not happy about their current status, and are actively seeking ways for their influence to rise again.