After being expelled from the Grand Coven, the powerful witch Rowena MacLeod had magical bindings placed upon her powers by the High Priestess Olivette. While these bindings failed to keep Rowena from performing powerful magic, they held in check the true extent of her powers.
In 2017, after being resurrected following her death for a second time at Lucifer's hands, Rowena began seeking the Black Grimoire in order to gain access to this ritual so that she could gain her full powers back. After dealing with Jamie and Jennie Plum, hunter Sam Winchester kept the Black Grimoire but provided Rowena with the page containing the ritual. That night, Rowena performed the ritual and regained her full powers.
After expending her magical energy in an attack on Billie, Rowena stated that she exhausted so much of her power that she doesn't know if she will ever regain what she lost. Gabriel, while talking with Rowena, referred to this as her unbinding not sticking though its unclear if this was the case or simply how Gabriel interpreted the story.
The witch in question must draw an elaborate symbol depicted in the Black Grimoire. Around the symbol lighted candles must be placed while the witch in question sits in a meditative posture within. More lit candles are placed in the room around the witch. The witch then recites the incantation:
- Ego sum filia naturae. Cum osculatione lunae. Da mihi vocem liberatem. Remitte vim meam. Fiem invicta.
- I am the daughter of nature. By Moon's kiss. Give my voice freedom. Look away from my soul. I will be invincible.
This spell is recited twice. As the incantation nears its end, the sigil on the corresponding page in the Black Grimoire glows.
After finishing the incantation, the witch opens a shallow cut in their throat. From the cut, glowing purple energy emerges and turns into the magical bonds that are binding down the witch's power. As the room shakes and blood pours from the witch's eyes, the magical bonds will shatter one by one until they are all gone.
Once the glowing bonds are gone, the cut opened in the witch's throat will heal, the blood coming from their eyes will disappear and a wind will blow out the candles on the sigil. The witch's full power is immediately restored and their eyes will glow blue to signify this.
- Given the Black Grimoire's nature as a tome of druidic magic, this ritual is most likely druidic in origin.
- Following the unbinding of her powers, Rowena's eyes begin to glow purple whenever she uses magic. Even after exhausting much of her power in an attack on Billie, Rowena's eyes retain this purple glow right up until her death in The Rupture.