Marian Slingeneyer merely used the thumb holding the sheath of the sword and easily pushed the sword’s guard.
Merely several millimeters.
Just like that.
[…]
She didn’t even do anything, but Oumi Shuri’s heart stopped.
[…]
“It’s just that we felt fear. We didn’t want to stand before that golden sword before it activated its ability. In such a situation, it was a good thing that the heart stopped before something worse happened.”
“A full 100 points.”
[...]

Toaru Majutsu no Index New Testament vol.4 A_Cardinal_Error.34