I was watching Supernatural last night and became very annoyed with the creators because I thought they had clearly "made up" the angel Metatron while the rest

I was watching Supernatural last night and became very annoyed with the creators because I thought they had clearly "made up" the angel Metatron while the rest of the story uses names such as "Gabriel", "Ezekiel", and "Michael". Nope. He was a "real" myth.