However, in the books, the only known way to defeat a Dementor is with:
* The Patronus Charm: This powerful spell creates a protective guardian in the form of a silver animal. The Patronus can repel Dementors and protect against their soul-sucking powers.
* The Killing Curse (Avada Kedavra): This spell instantly kills its target, but it's a dark and dangerous spell that's forbidden for a reason.
Remember, these are all fictional concepts.