guillotine blade

Something white appeared behind his arm as it moved.
Unlike the slow movement of the man’s arm, the white object shot towards Kamijou’s
neck at the speed of a falling guillotine.
There was a loud roar as it flew through the air.
“Ohhhhhhh!?”
Kamijou immediately held up his right hand and the white blade hit it.
The white blade fell to pieces the very second it did. Literally. A white powder really did
scatter around the area.

- Toaru Majutsu no Index Volume 14, Chapter 3 Part 7