In The Lord of the Rings: The Return of the King, Éowyn takes down the Witch-king of Angmar, but there's more to this feat than being a woman.
Éowyn succeeded in defeating the Witch-king of Angmar in The Lord of the Rings: The Return of the King, but the movie leaves out some important details about how she did it. Played by Miranda Otto, Éowyn is introduced in The Two Towers as a citizen of Rohan and the niece of King Theoden. With sexism even more popular than facial hair in Middle-earth, the battlefield is deemed no place for a woman, but Éowyn harbors a burning desire to protect her homeland against the oncoming forces of Sauron rather than taking shelter and waiting idly by. Along with Merry, now separated from the rest of the Fellowship and his Hobbit pals, Éowyn disguises herself and secretly joins the Battle of the Pelennor Fields outside of Minas Tirith.
Fighting bravely under the name Dernhelm, Éowyn proves herself a more-than capable warrior, and remains steadfast when faced with the Witch-king of Angmar, most powerful of the Ringwraiths. As established in The Fellowship of the Ring, these servants of Sauron are inherently difficult to kill by conventional means, but Éowyn confronts the Witch-king with a humble sword and wooden shield. In one of The Return of the King's most famous scenes, the Witch-king arrogantly proclaims that no man can kill him, to which Éowyn replies with her iconic "I am no man!" line and promptly slays him. Jackson's movie plays up Éowyn's femininity as the cause of her victory, but there's much more going on here.
Strangely enough, the Witch-king's fatal weakness isn't two X chromosomes. The death of the Witch-king is actually more a team effort between Éowyn and Merry. In the film, Éowyn is being held by the dark villain, but is released when her hairy-footed friend sneaks up behind the Witch-king and stabs him in the leg. The blade glows brightly and is then destroyed, as all weapons are when used on the Nazgûl. But an ordinary sword shouldn't bring the Witch-king to his knees.
Although altered in the movies, Merry's sword in the books is far from ordinary. The hobbit carries an ancient Barrow-blade that was crafted by men when Middle-earth was locked in war against Sauron's forces at Angbad. The weapon is quite literally designed to be used against dark magic, and was given to Merry by the mysterious Tom Bombadil, who isn't included in the Lord of the Rings movie trilogy. When Merry cuts the Witch-king, his blow is "breaking the spell that knit [the Witch-king's] unseen sinews to his will," which could be interpreted as opening the villain up to Éowyn's finishing strike straight through the hood. Since Merry receives his sword from Aragorn instead of Bombadil in the movie adaptation, its significance is lost. Moreover, the weapon Merry is given in the first film isn't returned after he and Pippin are captured by orcs. The blade he wields at the Battle of the Pelennor Fields in Jackson's trilogy is a replacement, but still has the same magical effect, creating somewhat of a plot hole.
The Witch-king's boast that no man can kill him comes from the elf Glorfindel, who foretold "not by the hand of man shall he fall." However, this line was always more of a symbolic prophecy than literal confirmation that men physically couldn't slay the Witch-king. Éowyn and Merry's victory fulfilled Glorfindel's prediction, but their gender and species weren't the deciding factors in bringing down the Ringwraith, it was a unique alignment of fated circumstances, which as Glorfindel predicted, didn't involve a man.
Some might argue that Merry's role in the Witch-king's demise dilutes the feminist message The Lord of the Rings sends with Éowyn's big moment, but all things considered, the full story makes Éowyn's arc even more powerful. Rather than being able to defeat the Witch-king simply because she's a woman, anyone on the battlefield could have felled the enemy under the right circumstances, but it was Éowyn whose courage and strength held out, making her victory all the more glorious.
