Patronus. The Patronus Charm is perhaps the most notorious difficult-to-cast spell in the wizarding world, and it's certainly the first one to come to mind for most fans. The Patronus Charm requires the caster to hold on to a moment of pure happiness—as in, they must think of their happiest memory.
Not only is it OP to just kill something so easily, but Avada Kedavra cannot be blocked or deflected by spells such as the Shield Charm. Only love itself, the strongest magic of all, can block the Killing Curse.
Tarantallegra. There are quite a few weird spells in the wizarding world, but perhaps the weirdest is Tarantallegra. It's similar to Rictumsempra in that it incapacitates and enemy in an unexpected way.
Unforgivable Curses are the three most powerful and sinister spells known to the wizarding world, and are tools of the Dark Arts. They were first classified as "Unforgivable" in 1717. They are the Killing Curse, Avada Kedavra, the Cruciatus Curse, Crucio, and the Imperius Curse, Imperio.
Nevertheless, while the impact of Avada Kedavra was unforgettable, Crucio was far more deadly than that, and Imperio as it could make a victim beg for death solely to stop the pain.
You will be sent to Azkaban if you use Avada Kedavra on students - Hogwarts Legacy
What spell killed Sirius?
The book and the films diverged. In the book he is not hit with the killing curse. I believe in the movie he is. In the book, the curse that hits Sirius is not identified (although it is rumoured to be Stupefy because of the red light), and him being knocked through the Veil is what causes his death.
The Disarming Charm became Harry Potter's signature spell, and it notably caused the final defeat of Lord Voldemort during the Battle of Hogwarts by rebounding his Killing Curse, because the Elder Wand recognised Harry as its master through the spell connection, and thus strengthened the Disarming Charm to the point ...
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.
In the final movie, Harry Potter and the Deathly Hallows pt. 2, Molly first hits Bella with a spell that freezes her, most likely Petrificus Totalus. Then, she launches another one that shatters her entire body into pieces, which could be expelliarmus, bombarda, stupefy, or any spell that can produce such an effect.
As the youngest Weasley, we're sure Ginny observed more than her fair share of unpleasant spells over the years but it was the Bat Bogey Hex she was famous for – and with good reason. This was the spell that overpowered Draco Malfoy and the Inquisitorial Squad, and also secured her an invite to the Slug Club.
The most dangerous spell in the Harry Potter series is Avada Kedavra (the Killing Curse). This spell is one of the three Unforgivable Curses, and it causes instant death to the victim.
One of the three Unforgivable Curses outlawed under wizarding law, Avada Kedavra kills the victim on impact, instantaneously and painlessly, usually with a blinding flash of green light. There is no way to block the spell, and there is no counter-curse - it can only be dodged.
In half blood prince:Gryffindor quidditch team selections, when it was Cormac's turn Hermoine casted the confundus charm and he missed his last save. We don't know about how she casts the spell in the book but in the movie it's shown that she just whispers "confundus" and that's it. Without a wand!
Although it is not confirmed to have been the Killing Curse, it is highly likely that Ron attempted to kill Voldemort's snake, and last Horcrux, Nagini, with Avada Kedavra. This is because, in the movies, Ron can be seen firing out a green spell at the snake, and it looks just like the Killing Curse.
Her fears were often centered around academic failure or expulsion, a fate she famously claimed to be worse than death. But Hermione also had a big heart, and the thought of anyone suffering — from house-elves to her nearest and dearest — frightened her to her core.
During the first Hogsmeade trip of the 1996–1997 school year, Draco Malfoy, having detention with McGonagall, had cast an Imperius Curse on Madam Rosmerta. She in turn, cast another Imperius Curse on student Katie Bell.
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.
It's implied that Septum Sempra is Snape's own creation, that he used a specific counter-curse to heal Draco, and that the spell isn't designed to be instantly fatal, but to inflict a gruesome, but relatively slow death if left untreated. It's likely Snape is the only person who knows said counter-curse.
During his final confrontation with Voldemort, Harry knew that he (Harry) was the Elder Wand's true master. He again cast Expelliarmus, ejecting the wand from Voldemort's hand into his own as the Killing Curse rebounded off his body, fatally striking Voldemort.
In the film, Bellatrix casts a blue spell at Ginny Weasley instead of a Killing Curse, who deflects it using a Shield Charm. In the book she just avoids it.
Yes, a skilled witch or wizard can counter or block the Expelliarmus spell, using spells such as **Protego** (the Shield Charm) or by simply evading it. The effectiveness of the defense often relies on the caster's skill and timing.
