The Hierarchy of Angels

The civil war in heaven raged on. Castiel was in danger of losing everything he fought so hard for. And with the rise of the Seraphim, the highest ranking & most powerful angels in heaven's hierarchy, even above the Archangels, the tides would inevitably turn, bringing new conflicts. What exactly does this mean for the civil war? For heaven? Or for Castiel? Castiel/OC/Gabriel