User blog comment:Greenberet69/The Witch-King vs. Durza/@comment-3528601-20120531192530/@comment-143604-20120601030039

1.) You're still wrong- when it's less of a real prophecy and more like a spoiler. In a crossover, all bets would likely be off anyway. And technically, depending on how you read into it, even a normal man could kill him in theory, because it's by no man's HANDS would he die. Cue Aragorn kicking him down the stairs. Or Theoden holding a sword in his mouth and impaling him on it. Sure, both ridiculous hyperboles, but the "prophecy" is vauge enough that any work around could work on him.

3.) That's...not exactly true. For example, at the beginning of Fellowship Aragorn is able to fend off the entire Nazgul and the Witch-King with them using a flaming torch and his blade, though he is able to do so without actually striking them. Eowyn landed a few blows before anything happened to her weapon, if I remember correctly. Various maybe-possibly-sort of-canon-from a certain perspective EU stories also feature the Witch-King being struck without the user's weapon being destroyed, such as BFMEII and The Third Age.