misaka worst railgun

He heard the sound of electricity sparking from behind him.
It was on a smaller scale than a Railgun from #3.
However, it was on a decidedly greater scale than the standard Sister.
He heard what sounded like a popping balloon.
It was the sound of an iron nail about 2 cm long being fired at just over the speed of
sound.
Its power was on the level of a handgun bullet.
The iron nail had been fired from behind Accelerator and it accurately pierced into his
left arm halfway between the elbow and shoulder.
It wasn’t that he hadn’t been able to reflect it.
He hadn’t been sure if he should reflect it.
No, what he couldn’t decide was if it was okay to kill the attacker by reflecting it.
He may have been able to alter the angle so it only injured her, but he could not deny the
fact that he might end up reflecting it and killing her due to a mistake or slipping back
into old habits. When he thought about that possibility, he could not act.
Strength left his arm.
The small girl it was supposed to be supporting flew through the air.
The warmth of the girl who was supporting Accelerator’s mentality was swept away by
the freezing cold that seemed to split through the snowy plain.
“Gaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhh!?”
His scream reverberated throughout the area.
Last Order’s body landed in the deep snow.
Accelerator could not even reach his arm out towards her. He lost his balance and
disturbed the white snow as he almost completely collapsed.

- Toaru Majutsu no Index Volume 20, Chapter 3 Part 2