Energy Focusing Sigil

An Energy Focusing Sigil is a sigil that magnifies energy. When drawn on an angel, and stabbed, the sigil will magnify the energy of the angel, and make him explode violently, and create a massive explosion, capable of destroying anything in certain radius (presumably mid-long range).

This sigil has been used by an unknown group of angels which worked under Metatron as we see in Stairway To Heaven. So far, the only known practitioner of this spell is Gadreel, which shown this spell in Do You Believe In Miracles?.

Procedure
An intricate Enochian Sigil must be placed in the chest of the spell's user. There are two ways known to place the sigil: by tattooing it (which has been shown in Stairway To Heaven by an unknown group of angels), or by carving it (as Gadreel showed in Do You Believe In Miracles?). The sigil on their vessel exposes them to earthly weapons, and such would then be able to kill them. The angel must then stab themselves on the sigil, and their grace explodes out of them, causing a massive explosion that kills anything nearby and blows the area up. Any other angels directly in the explosion's path are atomized. However, Gadreel survived this explosion while protecting Metatron but was severely hurt by it.

Trivia

 * This spell maybe closely related to Demon Bomb at some points (or maybe shared some similar characteristics and mechanisms). Except, the spell could affect anything, even human and building near it, like conventional bomb. Which Demon Bomb only affect demons in certain radius.
 * Tessa, who is a reaper, is also able to use this spell. Although it has never been tested, as Dean stopped her and destroyed the sigil before she was able to use the spell.
 * If there are humans existed in the place where an angel exploding him/herself, they will be mass-smited.

Appearance

 * Season 9
 * Stairway To Heaven (by Oren, Constantine, and Tessa)
 * Do You Believe In Miracles? (by Gadreel)