McGonagall was among the oldest and most experienced teachers in Hogwarts, and she was a worthy successor to Dumbledore as the headmistress. In fact, she has proven her mettle against Voldemort and survived a duel against him.
She was strong enough to kill Tonks (an auror). McGonagall had no such lack of discipline and was incredibly powerful in her own right. Bella was the only death eater that was able to deflect one of the spells from Dumbledore.
For example, in Harry Potter and the Deathly Hallows – Part 2, Snape was reluctant to fight McGonagall when the latter took him to a duel in front of Hogwarts students. Both characters had their strengths, but the last Harry Potter movie proved Snape was the strongest Hogwarts professor.
Her power and skills were such that even among her fellow highly brilliant faculty members, Minerva may very well have been the second most powerful and capable professor at Hogwarts, her command of magic surpassed only by Dumbledore himself, displayed not only by being the teacher who was chosen to represent the ...
Minerva McGonagall
She's the Head of Gryffindor and the most powerful witch in Hogwarts.
He also divided his soul into seven Horcruxes to make himself immortal. 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.
In the Harry Potter series, had Minerva McGonagall and Severus Snape both gone all out in a duel, who would have won? Severus Snape would win hands down, as evidenced by the clash of the seventh book or the eighth film.
Bellatrix is (kind of) in her prime, while McGonagall is old. We should also know that although Bellatrix is evil, it doesn't mean she's stupid. But seeing that McGonagall is old, we can correctly assume that she's experienced. I'd say McGonagall wins the duel, no questions asked.
Weaknesses. McGonagall is never portrayed as having any particular weaknesses. Her stern facade likely prevents anyone from getting close to her emotionally, with the possible exception of Dumbledore. We are led to believe that she prefers her solitude.
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).
Riddle is 9 years OLDER than McGonagall.
Minerva McGonagall
McGonagall was among the oldest and most experienced teachers in Hogwarts, and she was a worthy successor to Dumbledore as the headmistress. In fact, she has proven her mettle against Voldemort and survived a duel against him.
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.
Filius Flitwick is one of the many Hogwarts professors that are more powerful than Voldemort. He was a masterful wizard and an experienced professor.
1. Albus Dumbledore. Image Via Warner Bros. Dumbledore (Richard Harris and Michael Gambon) may not have been the one to ultimately defeat Voldemort, but he was frequently cited as the only person Voldemort ever feared -- meaning he was the main rival of both of the most infamous Dark wizards in modern history.
Bellatrix was his right-hand woman and when she was finally taken down, he bellowed out in rage at her passing. While she was certainly a powerful witch who earned Voldemort's trust, it's highly unlikely she could have defeated him in combat.
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.
None of the pupils had the power to cast Avada Kedavra. Not even McGonagall could cast it, and she was duelling to kill - she said so herself.
She is someone Voldemort respects as she is a tremendously powerful witch.
I'd say Kingsley, McGonagall, Moody, Bellatrix, Flitwick, and Snape together could beat Voldemort in a duel. So a total of 6 wizards.
25 Not Stronger: Bellatrix Lestrange
Voldemort himself wasn't more powerful than Dumbledore, and his followers, including Bellatrix, definitely weren't. Don't get me wrong, she was dangerous, and committed horrible crimes, but she wasn't as strong as Albus. After all, she was ultimately defeated by Molly Weasley.
This is precisely one of the reasons why Bellatrix was so engaging. She seemed to have a sick obsession with Voldemort that went so far beyond romantic desire. She was also very clearly scared of him and his remarkable magical abilities.
Later in the year, McGonagall duelled with Death Eater Alecto Carrow during the Battle in the Astronomy Tower and later learned of Snape's murder of Dumbledore. McGonagall was initially appointed as Headmistress, but was demoted after Voldemort took control of the school and placed Snape as Headmaster.
Professor McGonagall is a Death Eater
According to the theory, McGonagall's seeming disregard for Harry Potter's safety, her talent for transfiguration, and and her stoic nature all point to the fact that she was a Death Eater.
Originally Answered: How did Umbridge and other ministry members mange to get away with attacking Professor McGonagall in book 5? As Minister of Magic, Fudge was adamant to believe that Voldemort had returned.