How was Molly Weasley powerful enough to Kill Bellatrix Lestrange?

Question

I know the question of which spell was used has been asked (without really an answer) before. This is not a question of which spell or the series of spells cast. My question is how did Molly have the power to kill Bellatrix.

Harry Potter Book 7: Deathly Hallows:

Bellatrix was still fighting too, fifty yards away from Voldemort, and like her master she dueled three at once: Hermione, Ginny, and Luna, all battling their hardest, but Bellatrix was equal to them, and Harry’s attention was diverted as a Killing Curse shot so close to Ginny that she missed death by an inch—

He changed course, running at Bellatrix rather than Voldemort, but before he had gone a few steps he was knocked sideways.

“NOT MY DAUGHTER, YOU BITCH!”

Mrs. Weasley threw off her cloak as she ran, freeing her arms. Bellatrix spun on the spot, roaring with laughter at the sight of her new challenger.

“OUT OF MY WAY!” shouted Mrs. Weasley to the three girls, and with a swipe of her wand she began to duel. Harry watched with terror and elation as Molly Weasley’s wand slashed and twisted, and Bellatrix Lestrange’s smile faltered and became a snarl. Jets of light flew from both wands, the floor around the witches’ feet became hot and cracked; both women were fighting to kill.

“No!” Mrs. Weasley cried as a few students ran forward, trying to come to her aid. “Get back! Get back! She is mine!” Hundreds of people now lined the walls, watching the two fights, Voldemort and his three opponents, Bellatrix and Molly, and Harry stood, invisible, torn between both, wanting to attack and yet to protect, unable to be sure that he would not hit the innocent.

“What will happen to your children when I’ve killed you?” taunted Bellatrix, as mad as her master, capering as Molly’s curses danced around her. “When Mummy’s gone the same way as Freddie?”

“You — will — never — touch — our — children — again!” screamed Mrs. Weasley. Bellatrix laughed, the same exhilarated laugh her cousin Sirius had given as he toppled backward through the veil, and suddenly Harry knew what was going to happen before it did.

Molly’s curse soared beneath Bellatrix’s outstretched arm and hit her squarely in the chest, directly over her heart.

Bellatrix’s gloating smile froze, her eyes began to bulge: For the tiniest space of time she knew what had happened, and then she toppled, and the watching crowd roared, and Voldemort screamed.

From the quote above we see Bellatrix duelling three witches at the same time and equalling all three.

Bellatrix killed Sirius who was an expert in dueling. Bellatrix defeated Aurors (who are trained specifically to duel death eaters) Frank and Alice Longbottom.

If your answer is that Molly is angry please consider it already states in the above quote:

"...taunted Bellatrix, as mad as her master"

So I'd like some in canon proof that being angrier than someone during a duel overrides their ability and experience.

If for some reason your answer is that Bellatrix is not focused on her new opponent, please consider in the above passage:

Bellatrix spun on the spot, roaring with laughter at the sight of her new challenger.

If it's something about being protective of her children, please explain why this would matter in a dueling situation like this, unlike Lily's which was clearly self sacrifice and explained in great detail.

How could Molly a witch hardly trained in dueling with almost no comparable real life experience in dueling, beat one of the most powerful witches in the series?

Answer 1

JKR stated during her interview in Carnegie Hall that Molly was simply talented enough and also had the power of love on her side:

Question: How did you decide that Molly Weasley would be the one to finish off Bellatrix?

JKR: I always knew Molly was going to finish her off. I think there was some speculation that Neville would do it, because Neville obviously has a particular reason to hate Bellatrix. So, there were lots of options for Bellatrix, but I never deviated. I wanted it to be Molly, and I wanted it to be Molly for two reasons.

The first reason was I always saw Molly as a very good witch but someone whose light is necessarily hidden under a bushel, because she is in the kitchen a lot and she has had to raise, among others, Fred and George which is like, enough... I wanted Molly to have her moment and to show that because a woman had dedicated herself to her family does not mean that she doesn't have a lot of other talents.

Second reason: It was the meeting of two kinds of - if you call what Bellatrix feels for Voldemort - love, I guess we'll call it love, she has a kind of obsession with him, it's a very sick obsession ... and I wanted to match that kind of obsession with maternal love... the power that you give someone by loving them. So, Molly was really an amazing exemplar of maternal love. ... There was something very satisfying about putting those two women together.

Appearances aside, just because she didn't look or portray herself as an accomplished witch doesn't mean she wasn't one. The series focused on describing the talents and interactions of the new generation, leaving much of the older generation hidden in mystery. Additionally, it often described the power of love as the ultimate magic, which a mother protecting her children as the ultimate example.

Answer 2

It is not any one thing - and you actually pretty much cover all the factors in your question.

Molly is angry at Bellatrix - very specifically so. Her son has just been killed. It's already been shown in the books that strong emotion can lend greater power a spell.

Bellatrix is distracted - she's capering about like a loon (mad here means insane, not angry - angry people don't caper).

Molly is also a fairly accomplished witch - she is a surviving member of the original Order of the Phoenix, when many of them fell to the Deatheaters.

Sirius wasn't quite killed by Bellatrix - he was knocked into the portal and that was what killed him. Doesn't stop Bellatrix from bragging, but also means she wasn't the direct cause of his death.

And Lily didn't fight Voldemort to kill him - she put herself in the way to protect Harry. There's no indication that this was a duel.

So, all of this, all in one moment meant that Molly was able to strike with a killing blow and get past Bellatrix's defences.

Answer 3

It says in the books that Gideon and fabian Prewett fought like heroes and were talented wizards, I would have thought Molly would be the same.and given how gifted and intelligent all her children are, they inherit their skills from someone

Answer 4

In addition to the reasons listed in other answers, Bellatrix did not have her original wand when battling Molly Weasley. As explained in this answer, "[i]t's likely that using a different wand affected her dueling skills to some extent".

Answer 5

I agree with the argument that Bellatrix underestimated Molly. Bellatrix is mad, as in bat shit crazy, first of all, and so her judgment and reasoning can easily be questioned. At first she laughed at Molly's attempt to duel with her but grew wary when she was able to dodge and counter her own spells. It was described that the floor beneath the witches' feet became hot and cracked and in this you can see the intensity of their spells. Molly's proficiency in spellcasting can be seen in how she is able to maintain numerous spells in effect around the Weasley household all at the same time. Knowing the antics of her children and being an educated woman herself, she is not defenseless. Add that to how intent, focus, and emotion bolsters spells; she can undoubtedly cast powerful spells in that particular moment. Bellatrix then proceeded to taunt her even further and went into this typical villain speech and did not expect or anticipate a sudden attack from Molly, perhaps thinking that instead of Molly becoming more intent on killing her, she can make her grieve or more angry to the point of distractedness. It backfired, in the end.

Answer 6

To clear several things up, because there are a lot of facts being missed or outright ignored. Bellatrix was "a witch with prodigious skill and no conscience" trained by Voldemort himself, his "best lieutenant." She killed several Aurors, injured more, and even escaped Dumbledore himself (in the Death Chamber). Other wizards were "no match" for her. She did not kill Sirius with the Killing Curse - she stunned him and he fell through the veil. Also, Molly was in the newly formed Order of the Phoenix, not the original. Lily and James had "thrice defied" Lord Voldemort, and they were both members of the Order of the Phoenix, so saying that all she ever did was sacrifice herself for Harry is ridiculous. Bellatrix underestimated Molly. Plain and simple. Bellatrix did not consider Molly a serious threat.

Answer 7

It seems to me that the power of the witch or wizard comes from the ability to protect an emotion into any given spell. Voldemort is powerful because of his ability to project his hatred into spells, Bellatrix is psychotic and lives in a world of tumultuous emotions. The message here is that love is the most powerful of emotions. It makes one speculate that Ginny, who was extremely powerful even as a little girl, must be a very passionate person. Harry is in for the ride of his life.