This spell was first demonstrated to the Winchester brothers by Anna in the season 4 episode Heaven and Hell. Dean later watched Castiel draw it on the wall in the Green Room to banish Zachariah. When Zachariah comes for him in the episode Sympathy for the Devil, Dean reveals to have drawn it on a sliding door and promptly sends Zachariah away using the sigil. He claims to have learned it from Castiel despite having first seen Anna use it. Following this, the Winchesters use it as an effective means of defending themselves against enemy angels, particularly in I Think I'm Gonna Like It Here and The Vessel when Dean is unable to defeat two enemy angels and Sam uses it to banish Lucifer. Metatron later attempts it on Amara to no effect in All in the Family. All angels are effected by the sig