Avada kedavra present in work Harry Potter
Priori Incantatem
Priori incantatem (from Latin: priorem incantatum – a previous spell), or the reverse spell effect, is used to display the spells cast by a wand. The spells cast by the wand will emerge in smoky or ghost-like replicas in reverse order, with the latest spell emerging first. It is first encountered in Goblet of Fire when Barty Crouch Sr.'s house elf Winky is caught holding Harry's wand. This spell is used to reveal that it was indeed Harry's wand that was used by Crouch's son to cast the Dark Mark. In Harry Potter and the Half-Blood Prince, it is revealed that the teenage Voldemort murdered his father and grandparents using his uncle Morfin's wand, knowing that, when examined, the wand would incriminate Morfin as the murderer. In Deathly Hallows, Harry fears that a priori incantatem spell will be used on Hermione's wand after the Death Eaters get hold of it. This would reveal that she had accidentally broken his holly-and-phoenix-feather wand when a curse misfired and they both narrowly escaped Voldemort earlier. As a result, the protection of the shared cores was lost and, worse still, this would now be made known to Voldemort. During the final duel between Harry and Voldemort, the latter mentions that he knows that the holly and phoenix wand is destroyed, implying that the priori incantatem has indeed been performed on Hermione's wand, as they had feared.
Forcing two wands that share the source of their cores to do battle can also cause a more potent form of priori incantatem. The tips of the two wands will connect, forming a thick golden "thread" of energy, and the two wands' masters fight a battle of wills. The loser's wand will regurgitate shadows of spells that it has cast in reverse order. This phenomenon occurs during the duel between Harry and Voldemort at the end of Goblet of Fire. Their simultaneous spells (Harry casts "expelliarmus" and Voldemort casts "avada kedavra") trigger the threads, and as Voldemort loses the battle of wills, his wand regurgitates, in reverse order, echoes of the people his wand had most recently murdered: Cedric Diggory; Frank Bryce; Bertha Jorkins; as well as Harry's parents.Horcrux
A horcrux is an object created using dark magic to attain effective immortality. The concept is first introduced in the sixth novel, Harry Potter and the Half-Blood Prince, although horcruxes are present in earlier novels without being explained or identified as such.
To create a horcrux, a witch or wizard must first prepare the chosen object in a ritual which Rowling described only as “too horrible to go into detail about”. Following the preparation of the object, the witch or wizard must then take a life, an act which splits the soul. Following that, further dark rituals are required in order to remove the soul shard from the maker and place it into the prepared object. Once this is done, the horcrux becomes magically protected from almost all forms of destruction, requiring extremely powerful magic or especially destructive substances to do so.
Ordinarily, when one's body is killed, the soul departs for the next world. If, however, the body of a horcrux maker is killed, that portion of his soul which was still in his body will not pass on to the next world, but will rather exist in a non-corporeal form capable of being resurrected by another wizard. If all of someone's horcruxes are destroyed, then his soul's only anchor in the material world would be his body, the destruction of which would then cause his final death. To destroy the horcrux, the destroyer must destroy it in such a way that it is put beyond magical repair. In the second book, Tom Riddle's diary (later found to be a horcrux) is destroyed by Harry with a basilisk's venomous fang. In the seventh book, Gryffindor's sword, which is impregnated with basilisk venom, an old basilisk fang, and fiendfyre are the substances used to destroy them.
featured in work appears in work mentioned in work depicted in work portrayed in work