Avada Kedavra It's used to kill people, it's an Unforgivable Curse, and it was Voldemort's favourite, so it's going last.
1 Avada Kedavra Is Just Ridiculous
Only love itself, the strongest magic of all, can block the Killing Curse. Lord Voldemort cast this spell constantly in his lifetime, and it's the spell that killed Harry's parents in particular.
5 Bellatrix Lestrange: The Cruciatus Curse.
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.
Hermione's de facto signature spell is 'Bluebell Flames', also known as 'Cold Flames'. The incantation is unknown but is at least 2 words long. Hermione uses it 4 times: Once to set Snape's robe on fire in the Slytherin-Gryffindor Quidditch Match in their 1st Year.
Muffliato. This was the spell, the spell, Draco would use whenever Potter or Weasley tried to listen in on his and Hermione's conversations.
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.
Sectumsempra was invented by Severus Snape, and was thought to be his signature move, as Lupin noted after the Battle of the Seven Potters.
He recites: "Sunshine, daisies, butter mellow, turn this stupid, fat rat yellow." Unfortunately for Ron, the rat doesn't turn yellow and Hermione instantly shows him up by magically repairing Harry's glasses.
Sectumsempra was a curse invented by Professor Severus Snape that lacerates the target and causes severe haemorrhaging.
Firestorm. Firestorm was a spell that created a large ring of fire around the caster's wand. This spell is one of the last and most powerful spells that Albus Dumbledore cast using the elder wand before his death.
Cruciatus Curse ('Crucio')
Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius.
The three curses that are classified as Unforgivable are the Imperius Curse, the Cruciatus Curse, and the Killing Curse.
If Lord Voldemort wasn't one of the most evil wizards the wizarding world has ever known, then he would surely be remembered as one of its most brilliant. Case in point: he achieved what was long thought to be a magical impossibility, and invented a spell that allows the user to fly.
The Reductor Curse can blast solid objects into pieces with minimal effort. Over the course of the Dumbledore's Army lessons in The Order Of The Phoenix, Reducto becomes the unofficial spell for Ginny Weasley.
The bluebell flames spell
As we discover in Chamber of Secrets, 'conjuring up portable, water-proof fires was a speciality of Hermione's'. While she used this skill for setting Snape's robes alight, brewing Polyjuice Potion and keeping people warm, we also think it'd be mighty useful for aesthetic reasons.
Alohomora, which is a spell that unlocks objects (and it's also Hermine Granger's signature spell).
Hermione's bluebell flames
Hermione first uses it against Snape when she and Ron think he is cursing Harry's broom in his first Quidditch match. Her bright blue flames set Snape's robes alight, before Hermione scoops them up and puts them into a jar.
When Snape killed Dumbledore. In probably the most shocking twist of the series, Snape cast the unforgivable Avada Kedavra curse on Hogwarts' beloved headmaster.
Hermione cast a bluebell flame that could be carried around in a jar. She used it to set Snape's robes on fire during the match between Gryffindor and Slytherin of her first year. Hermione used this spell against Devil's Snare when she, Harry, and Ron worked through the challenges surrounding the Philosopher's Stone.
Dumbledore's Forceful Spell. Albus Dumbledore's forceful spell is a spell of his own invention intended to reveal the number of times one's soul has been split and detached and possibly even the location of those split soul fragments. It's like a weird version of Homenum Revelio but – you know – for souls.
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.
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.