Protego Diabolica

Protego Diabolica
Incantation	Protego Diabolica (proh-TAY-goh dia-BOHL-i-cuh)
Type	Dark charm
Effect	Encircling the caster with a protective ring of black fire that incinerated enemies and left allies unharmed

"It is a very powerful dark charm. It creates a protective ring of black fire that harms enemies of the caster."

— Description

Protego Diabolica was the incantation of a powerful and dangerous protective dark charm that encircled the caster with a protective ring of black fire that incinerated the caster's enemies while leaving their allies unharmed. The black fire also took the appearance of winged creatures that spread rapidly and were capable of great destruction. It was similar to, but different from the Fiendfyre curse.

Description and effects

Krall being incinerated by the fire, due to his disloyalty to Grindelwald

When conjured, the black fire produced by Protego Diabolica followed the caster's control, and could be directed to create a ring of protective fire around the caster and their allies that incinerated any enemy of the caster. The caster could also control it to attack specific targets in the form of tendrils of fire that extended from the ring, along with having the flames take the form of winged creatures that spread rapidly, and were capable of incinerating an entire city or large area if not extinguished. The black fire also protected the caster from certain offensive spells from outside of the protective circle.

Vinda Rosier crossing the fire, due to her loyalty to Grindelwald

Krall, having had recently reserved himself from his master's side due to his disloyalty, was incinerated to ash immediately upon entering the black fire created by Gellert. Leta Lestrange was initially allowed to cross through Grindelwald's protective fire by appearing to show loyalty to him, however as she immediately turned on him and Vinda Rosier and destroyed his skull-hookah when she entered, Grindelwald had the flames engulf and incinerate her.

Counter and treatment

Jacob recovering from the effects of this spell in St Mungo's

Mediwizard: "I've never seen someone who's survived 'Protego Diabolica'... your brother is quite lucky!"

Healer: "The recovery your brother made is quite miraculous! I can hardly believe it..."

— The rare survivability

It was a very rare occurrence for a victim to survive being burned by the flames of Protego Diabolica, requiring the injured victim to undertake proper medical treatment afterwards in order to improve their health and recovery, if the wounds were not instantly fatal to them. Burn-Healing Paste was insufficient in treating these burns.

The General Counter-Spell could extinguish the black fire, which could also be deflected via the usage of the Shield Charm.

History

Grindelwald controlling the fire to separate his enemies from his allies

"Aurors, join me in this circle. Pledge to me your eternal allegiance, or die. Only here shall you know freedom, only here shall you know yourselves. [...] Play by the rules! No cheating, children!"

— Gellert Grindelwald to the Aurors trying to flee from his spell

In early September 1927, Gellert Grindelwald cast this spell in the Lestrange Mausoleum in Paris to test the loyalty of his followers and kill a number of his enemies, most of whom were Aurors trying to arrest him. Because they were loyal, Vinda Rosier, Abernathy, Nagel, MacDuff, Carrow, Krafft, Credence Barebone and Queenie Goldstein all passed through the fire into the circle. Krall, who considered turning against Grindelwald, failed to enter. Several victims who never attempted to cross either escaped the ring or fell to its wrath. The black flames were eventually dispelled by the combined efforts of Theseus and Newt Scamander, Porpentina Goldstein, Yusuf Kama, and Nicolas Flamel following Leta Lestrange's self-sacrifice, effectively saving the entire city of Paris from Grindelwald's fury and destruction.

During the 1990–1991 school year, Jacob travelled to Japan, believing R was after a legendary artefact after he gathered evidence from different captured R members. He discovered half of the Dark Scroll in a mountaintop cave and was severely burned with Protego Diabolica, with which the Dark Scroll was protected. Jacob was then sent to St Mungo's back in England, where he was treated for his injuries. After Healer Miriam Strout healed his burns and saved his life after adjusting his treatments accordingly to the helpful advice by Albus Dumbledore, Jacob told his sibling about his venturing in the cave and that he had deduced that "R" had already been there and took the other half of the scroll in order to brew Dai Ryusaki's mind-enhancing potion, as he only found one torn half of it.

Known uses

Caster	Date	Victim	Description
Unknown	Prior to 22 June, 1691	Jacob (indirectly; survived) R members (indirectly; possibly)	Jacob was affected by this spell when he found the Dark Scroll in the mountaintop cave in Japan.
Gellert Grindelwald	Early September 1927	Krall Many Aurors Leta Lestrange	Gellert used this dark charm in the Lestrange family Mausoleum in Paris to test the loyalty of his followers, and kill a number of his enemies, including Aurors.

Known practitioners

"I seem to recall it being a favourite of the current headmaster of Mahoutokoro."

— Albus Dumbledore regarding Protego Diabolica to Jacob's sibling

Gellert Grindelwald

• Headmaster of Mahoutokoro during 1990
• Unidentified Muggle-born Hogwarts student

Etymology

• The incantation comes from Latin "protego", "I protect", and "diabolica", a declension of "diabolicus", meaning "diabolic, relating to the Devil".
  • It is unclear if the translation is meant to suggest "protection from the devil" or "the devil protects". As the spell is used to divide friend from foe, one can assume that the former translation is accurate, as Grindelwald was dividing himself from those whom he considered "the enemy" (also a euphemism for Satan). However, given Grindelwald's real intentions and his habit of using irony and misleading phrases (such as the phrase "The Greater Good" when he is, in fact, inflicting suffering rather than good), it could very well be the latter.

Behind the scenes

• In Fantastic Beasts: The Crimes of Grindelwald - The Original Screenplay, the spell creates a "circle of black fire", whereas in the film the flames are bright blue. This is most likely due to the other tones of the scene being too dark for black fire to properly be seen. Therefore, blue fire might have been used instead to show contrast to these dark tones.
  • In Harry Potter: Magic Awakened, the flames are also bright blue.
• The spell was similar to the Fiendfyre curse, as it created a highly dangerous fire, including creating an entire pack of winged creatures that could be directed to an extent, and incinerate a large area, although the General Counter-Spell could extinguish it. However, the flames produced by Protego Diabolica were harmless to the caster and their allies (only incinerating those who the caster considered to be enemy or a threat), while Fiendfyre destroyed everything that came into physical contact with it.
  • Also, it is similar to the black and purple flames that Severus Snape added to the protections for the Philosopher's Stone before it was eventually recovered and destroyed. The flames of Protego Diabolica and the black and purple flames have specific ways of being crossed unharmed.
• It is one of the duelling spells available to students in Harry Potter: Magic Awakened, where it is classed as a legendary spell. In this game, casting Protego Diabolica causes a ring of blue fire to erupt around the player character, damaging all enemies inside the circle whilst three successive waves of flaming dragons are launched at the opponent. Despite being Dark Magic, the player does not have to remove it from their deck for story missions, like they would for other spells such as Avada Kedavra or Crucio.
• In the film adaptation of Harry Potter and the Half-Blood Prince, the spell used by Bellatrix Lestrange during the non-canonical Burning of the Burrow has similarities to Protego Diabolica, as it created a ring of fire that only allowed Bellatrix, Harry Potter, and Ginevra Weasley through while leaving the others to deal with the flames and extinguish them, holding them back. It is also similar to the cursed barrier that was used during the Battle of the Astronomy Tower.

Appearances

• Fantastic Beasts: The Crimes of Grindelwald - The Original Screenplay (First appearance)
• Fantastic Beasts: The Crimes of Grindelwald
• Harry Potter: Hogwarts Mystery (Mentioned only)
• Harry Potter: Magic Awakened