The fact that the sword was invisible up to a certain point in time when it was supposedly "created out of thin air" does not mean it was in fact created out of thin air. That's the most common magician's trick, making things appear "out of thin air". I'm not saying that there's nothing to Talzin's use of the Force, just that it is overwhelmingly based on theatrics and misdirection to make her appear far more powerful than she is. That's the whole purpose of chanting before casting one's spells, to draw attention from your sleight-of-hand. Edit: I watched The Prestige again last night (and was reminded that it has of the wonkiest film premises ever), and I'd say I see Talzin's magic as The Real Trasported Man act was presented in that film: there's an extraordinary, apparently supernatural truth at its core, but it is dressed up with illusionary tactics.