Okay, so in 'The Lion, the Witch and the Wardrobe', the White Witch isn't defeated by any one character in a sword fight or anything obvious like that. Her power rests on something called the Deep Magic from the Dawn of Time, which says traitors (like Edmund) belong to her. Aslan makes a deal to sacrifice himself in Edmund's place, which she accepts thinking she's won. What she doesn't understand is the Deeper Magic from Before the Dawn of Time, which says if a willing innocent victim is killed in a traitor's place, Death itself starts working backwards.
Aslan comes back to life and then just... wrecks her whole army. He breathes on her statues and they come back to life, and then in the final battle, it's Peter and the army fighting her forces while Aslan goes straight for her. I always thought the actual defeat was kind of quick? Like, she turns a bunch of people to stone, but Aslan just pounces and it's over. The real victory was the sacrifice and breaking her claim on Edmund, which shattered her legal right to rule. The battle was just cleaning up the mess. The witch was undone by her own failure to grasp a magic older and deeper than her own, which is a way better ending than just stabbing her.