In the film, Snape is forced to fight Professor McGonagall after Harry Potter reveals that he was the one that killed Professor Dumbledore (at Dumbledore's bidding, though at the time the fact was unknown). Interestingly, Snape defends himself against the witch – but doesn't actually fire back.
In the novel, the duel between McGonagall and Snape plays out somewhat differently; she did use fire at one point in their duel, though it was through using the fire from burning torches along the walls, not through conjuring flames from her wand.
However, Harry's return seemed to ignite a fire in McGonagall, who quickly went to find her abhorred boss Snape to curtly inform him of events. Before long, a frankly awesome duel ensued between McGonagall, Flitwick, Sprout and Snape, the three fellow professors chipping in to end Snape's reign once and for all.
Both characters had their strengths, but the last Harry Potter movie proved Snape was the strongest Hogwarts professor. McGonagall's transfiguration reputation spoke for itself.
They are on their way to alert the heads, with Harry and Luna hidden under the cloak, when they meet Severus Snape in the hallway. When Snape demands to know if McGonagall has seen Harry Potter, she attacks him, and they duel.
In the film, Snape is forced to fight Professor McGonagall after Harry Potter reveals that he was the one that killed Professor Dumbledore (at Dumbledore's bidding, though at the time the fact was unknown). Interestingly, Snape defends himself against the witch – but doesn't actually fire back.
McGonagall followed up Harry's action by using the Imperius Curse on Amycus before tying him up with a net, rendering him useless during the Battle of Hogwarts.
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.
Winner: Snape
The kind of versatility in magical abilities that Snape displayed was almost around the level of Albus Dumbledore and Voldemort, making him easily more powerful than the average wizard and even the members of the Order of the Phoenix and the Death Eaters.
Godrick Gryffindor, one of the four founders of Hogwarts, and the owner of the legendary Sword of Gryffindor, was absolutely more powerful than Dumbledore— and it's a good thing he was, too, because Dumbledore wasn't around in Hogwarts' early days to keep Godrick's fellow founder Salazar Slytherin in check.
Severus Snape is one of the most divisive characters in the entire "Harry Potter" series. He was a double agent, so many character details were kept a secret. His mother was a witch and his father was a Muggle, leading to the moniker "The Half-Blood Prince."
When Harry is "killed," the first person to react is McGonagall and her shriek shocks Harry so much. When the battle is over, and the Dark Lord dead, she is one of the first to hug Harry for saving mankind. Throughout the series, Minerva McGonagall was consistently a stable, strong and supportive figure for Harry.
Thankfully, Hogwarts' Board of Governors appointed McGonagall as Headmistress after Snape's death, a title which she still holds in the series' current timeline.
Why did Snape not defend himself against Nagini? Because Voldemort beleive that elder wand belongs to Snape but acctually it belongs to Melfoy. So Snape made voldemort belive that if he kill snape then the wand will belongs to him. So Snape didn't defend himself from nagini.
Weakness: His tendency to bully others
Other than the Slytherins, Snape bullied almost anyone, especially those he saw as weak or a threat to him.
Also, Snape stands out as a truly uniquely powerful wizard and edges out Voldemort thanks to two things: his knack for the dark arts, and his incredible capacity for love. You have to remember that in the Wizarding World, like it or not, love is the most powerful kind of magic.
Molly Weasley, the mother of 7 children, is probably one of the most powerful witches I am going to discuss in this article.
1. Albus Dumbledore. Albus Dumbledore, 'Considered by many the greatest wizard of modern times' as it says on his Chocolate Frog card, is top of our duelling second wish list.
"It does not do to dwell on dreams and forget to live"
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.
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.
Dumbledore, at one point, possessed all three Deathly Hallows. From Dumbledore's letters to Grindelwald in Deathly Hallows, it is obvious that the headmaster of Hogwarts was obsessed with the idea of the Hallows in his youth.