|“||They don't listen, Castiel, because their hearts are mine.||”|
Raphael's followers were angels who chose not to follow Castiel, a newly-proclaimed hero at the time, and stick with accepting the archangel as their ruler. They are first seen guarding Ken Lay's Heaven which Raphael was "borrowing" in order to speak to Castiel.
Most of Raphael's followers fought against Castiel Loyalists in Heaven. The tides were turned in the latter's favor when Castiel obtained the souls of Purgatory and was able to obliterate Raphael. Upon declaring himself the new God, Castiel went about killing anyone who opposed him.
Castiel purged Heaven of any and all of Raphael's remaining followers.