[s9e6] Heaven Can't Wait -

The episode expanded the lore of the angel hierarchy by introducing the concept of celestial field medics.

The Rit Zien targets Castiel after sensing his internal sadness. Dean arrives in time to help Castiel defeat the angel, though the encounter serves as a grim reminder of the chaos currently reigning in Heaven. Major Themes [S9E6] Heaven Can't Wait

These were celestial medics who performed mercy killings on mortally wounded angels on the battlefield. On Earth, this angel has begun "mercy killing" humans who are experiencing even minor emotional distress. The episode expanded the lore of the angel