The translation here seems a bit iffy...seems the word "sword" is missing early on, and at the end, was the dialogue really like that?: "But because Iver was confused and unable to see through the true identity of the sages. And then, she--She failed to see through the true identity of the sages."
Like weird grammar aside, you just said that...
That said, the concept behind this scene itself is pretty meh. Deus ex machina has never been enjoyable. This is a total asspull.