The three Unforgivable Curses are the Cruciatus Curse, which causes unbearable pain; the Imperius Curse, which allows the user to control the actions of the victim; and the Killing Curse, which causes instant death.
They are the Killing Curse, Avada Kedavra, the Cruciatus Curse, Crucio, and the Imperius Curse, Imperio.
Confringo. Commonly known as the Blasting Curse, Confringo causes the target to explode. To make it even more dangerous, it produces flames that ignite upon contact with the target. If Confringo fails to kill the target immediately, they will instead suffer a slow and painful death.
Along with the Cruciatus Curse and the Imperius Curse, Avada Kedavra is considered to be one of the most terrible curses in the magical world, called the Unforgivable Curses; the use of any of the three on another witch or wizard is punishable by a life sentence in Azkaban.
The Killing Curse was created in the early Middle Ages by Dark witches and wizards. Primarily, the curse was used to quickly slay opponents during a duel. In 1707, the Wizards' Council was restructured into the Ministry of Magic, which allowed for more strict restrictions on certain types of magic.
"Sectumsempra is a curse invented by Professor Severus Snape, during his childhood, when he was known as "The Half-Blood Prince" He created it with the intention of using it against his enemies, and it soon became one of his specialties."
Albus Percival Wulfric Brian Dumbledore was the only wizard Voldemort ever feared and the only one who could have defeated him in a duel. Albus Dumbledore is the most powerful wizard in the Harry Potter.
Some would say there's no spell worse than Avada Kedavra, the Killing Curse that Voldemort used so indiscriminately.
Harry makes use of two of the Unforgivable Curses in the books. Dueling with Bellatrix Lestrange, he attempts the Cruciatus curse, with limited results; Bellatrix says that he has to really hate someone to make the Unforgivable Curses work properly, righteous indignation isn't enough.
Expelliarmus did not beat Avada Kedavra.
Voldemort's wand (the elder wand) recognized its true master (that was Harry) and refused to attack it. In a way Voldemort killed himself as his own spell backfired on him.
Merlin's beard/Merlin's pants
Merlin's beard, Merlin's “baggy y-fronts,” Merlin's pants, or simply just his name are all common curses uttered by the wizarding community in times of surprise or crisis.
The least-used spell: Waddiwasi, used in Harry Potter and the Prisoner of Azkaban, which is “the incantation of a charm that can be used to shoot a small, soft mass of whatever the caster so desires at the target or victim,” according to the Harry Potter Wiki.
Though Harry encountered many opportunities that deemed Avada Kedavra necessary, the wizard never cast, or even considered casting, that particular spell. For one, he viewed the spell as an immoral practice commonly used by users of the Dark Arts.
Harry became so enamoured with the spell that he eventually used it to finish off Lord Voldemort. Here's how Harry's relationship with Expelliarmus became his signature – and why that's a good and bad thing.
After being on the run from a bunch of Snatchers, the gang were taken to Malfoy Manor, where Bellatrix proceeded to torture Hermione using the Cruciatus Curse.
Malfoy spots Harry and casts a Cruciatus curse; Harry, defending himself, using the Half-Blood Prince's Sectumsempra spell without knowing its effects. To his horror, it gashes Draco's face and chest, spilling his blood everywhere. Moaning Myrtle flies off, screaming.
Today Years Old shared side-by-side photos of Harry's scar and the hand motion for casting the Avada Kedavra spell. As fans of the books/movies know, this is the spell Voldemort used when he first attempted to kill baby Harry. The killing curse failed, of course, because of Lily Potter's sacrifice to save her son.
In the books it is revealed that Harry Potter got the scar when he was attacked by Voldemort, who had just murdered his parents. Voldemort launched the killing curse "Avada Kedavra" at baby Potter but the spell rebounded. It was the only time someone had been hit in the face by the curse and survived.
Transfiguration: Sirius, along with his friend Remus, could perform human transfiguration on Peter, forcing him out of his Animagus form. Non-verbal magic: Sirius was able to perform human transfiguration and defensive magic such as Disarming and Stunning spells non-verbally.
Lord Voldemort
Tom Marvolo Riddle started both Wizarding Wars, created the Death Eaters and killed Harry Potter's parents. We could go on – he was the most dangerous Dark wizard of all time – but we won't. His horrific achievements are well known.
Dobby frequently demonstrated himself to be immensely powerful, causing Lucius Malfoy himself to back down with just a point of his finger. Kreacher was so powerful that he was able to Disapparate where wizards could not, escaping the Inferi that surrounded the locket Horcrux.
That's debatable. He survived the Avada Kedavra curse, but that was thanks to his mother's love and protection; without Dumbledore's tutoring, Harry may not have been able to defeat the Dark Lord at all. Yes, Harry Potter was a brilliant wizard and a hero, but he was not stronger than Dumbledore.