[Many Greek gods had their own angels, or Eudaemons.]

[Eudemons were more than just the Christian angels were, they were regarded intermediary spirits between gods and the men. Eudaemons, the good daemons, were understood as guardian spirits, bestowing protection and guidance to ones they watched over. The Eudaemon could whisper advice and opinions into one's ear, almost all serving as guardian angels.]

[But the reason Castiel had been assigned one to help him with the Winchesters? He had no clue.]