>>719867645
That's not even the issue. Astra can fucking teleport and power Ether engines with her voice. People with high Ether Aptitude have super powers, we know this.
The problem is that in the cutscene where Miyabi is first introduced, when she attacks Nineveh, she's clearly telling the sword spirit that it's Go Time. If she could do what she does with any sword then there would be no point to her using the Demon Sword at all and the whole fingerprint lock on the sheath is nonsense.