Fiendfyre

Biodata

Characteristics

Fiendfyre is an exceptionally dangerous form of Dark Magic, described as a “devil’s flame.” It spreads rapidly, is difficult to control, and can take the form of predatory fire creatures under a capable caster’s command 138 489 534.

• Its flames have appeared as a spreading firestorm, a line of advancing fire, snakes, dragons, and a giant humanoid shape 138 434 489 534 535.
• It can consume Transfigured creatures almost instantly; a Black-Robed wizard’s Fiendfyre reduced Scott’s Fire Ravens and Balrog-like construct to fragments 434.
• Fiendfyre can destroy objects resistant to ordinary Charms. Dumbledore used it to completely destroy Tom Riddle’s diary Horcrux 168.
• It is identified as the true weakness of Killing Fluid Alchemy Puppets, as it can burn matter to ash 542.
• Ordinary water cannot extinguish it, though water can briefly obstruct its spread 534.
• A standard Magic Barrier provides only momentary protection, since Fiendfyre can burn the barrier itself 534.

Emotional Control

Fiendfyre requires dark emotions—particularly hatred—to sustain the caster’s control. Scott deduced that genuine happiness can interfere with this requirement after using a Cheering Charm on Brandon Yaxley 138.

• The Cheering Charm did not harm Yaxley and therefore bypassed his defensive magical item 138.
• Once Yaxley was overwhelmed by happiness, he lost control of the Fiendfyre; it turned back toward him and Elijah Carrow 138.
• Professor Flitwick later praised this as an especially suitable countermeasure for young wizards 168.

Suppression and Dispersal

• Finite Incantatem — Dumbledore extinguished Yaxley’s rapidly spreading Fiendfyre with a large-scale Finite Incantatem powered through the Elder Wand 138.
• Wind magic — Horus’s Gale dispersed a Fiendfyre python created by Voldemort, although it did not destroy the fire itself 490.
• Evasion and delay — Scott used a Shield Charm for a split second of protection, then Apparition and Animagus transformation to escape Voldemort’s Fiendfyre 534.

Documented Casters

Story Role / Major Incidents

• Forbidden Forest challenge — Yaxley cast Fiendfyre while attempting to ambush Scott during Scott’s Acromantula challenge. Scott’s Cheering Charm broke Yaxley’s emotional control, causing the fire to pursue Yaxley and Carrow until Dumbledore extinguished it 138.
• Diary Horcrux destruction — Dumbledore revealed that Fiendfyre was the dangerous spell he had used to destroy Tom Riddle’s diary 168.
• Seaside cliff ambush — A Black-Robed wizard’s Fiendfyre overwhelmed Scott’s Transfigured forces and forced Scott to escape over the cliff in Peregrine Falcon form 434.
• Battle of Hogwarts — Voldemort shaped dark-red Fiendfyre into a giant serpent to attack Hogwarts’ protective barrier and later targeted Scott’s water-element Summoned Beast with a Fiendfyre python 489 490.
• Battle against Voldemort — Voldemort flooded the battlefield with Fiendfyre, destroying Scott’s hidden Runes Circuits and forcing Scott and Harry to shelter in a Different Dimension 534. After Voldemort fell, the remaining flames formed a giant in his likeness before gradually diminishing 535.
• Avalon conflict — Medea employed Fiendfyre in conjunction with a Disposable Philosopher’s Stone, shaping the flames into beasts that burned through Savanna’s animated plant defenses 574.

Trivia

• Scott has never learned Fiendfyre, despite recognizing its usefulness against Horcruxes and Alchemy Puppets 540 541 542.
• Scott chose to seek more advanced knowledge of Gungnir rather than learn Fiendfyre as a means of destroying a Horcrux 541.