Kihara Byouri twisted her body up from her lying position and fired the metal nail in her right hand toward the source of the noise. She did not particularly care who it was. She merely fired the ultra high speed sniper shot at the target’s forehead and her aim was spot on.
The person was wearing a coat.
The person was wearing a full face helmet.
The thick nail sank into the forehead of the helmet and countless large cracks ran through it. The full face helmet completely shattered in less than a second. With the hard helmet destroyed, the person’s face was revealed.
His face was unscathed.
Normally, his skull would have been destroyed and gray matter would have spewed out.

Toaru Majutsu no Index New Testament vol.4 main.30