flame sword burst

Before the dazed sisters could re-form their ranks, Stiyl and Tatemiya stormed in. Stiyl’s
flame sword exploded, and the sisters pressed flat to the ground by the waves were
skillfully knocked unconscious one by one by Tatemiya. Meanwhile, a little farther away,
Index’s casual whisperings were blasting tons of the sisters surrounding her all over the
place.
Tatemiya was half-impressed and half-amazed. “With a hidden ball trick like that, why
didn’t she use it right from the start? And if she’d used it against us, she could’ve mowed
us all down!”
“It’s a delicate attack, and there are frustrating limitations. Religious brainwashing is
easier to pull off on a group all at once than on an individual basis. You understand that,
right? Sheol Fear uses what they call group mentality in science to break through the
barriers of their minds and use them as footholds.”
Stiyl caused his flame sword to burst, repelling the sisters edging toward him. One of
them who tried to time her attack came away with a scalding burn on her cheek and
quickly jumped away.

- Toaru Majutsu no Index Volume 7, Chapter 4 Part 2