teleport weakness

Shirai’s ability was called Teleport. It was not limited to three dimension rules, so she
could move about freely within space.
But it had a weakness. She couldn’t just warp around however she wanted. It went beyond
three dimensions—the ability required her to derive her current spatial coordinates in
eleven dimensions, then calculate her movement vector from there. The commands she
needed to give were on a completely different level than those of normal espers, who could
just think phrases like “create fire” or “make lightning.”
Because of that, if anything were to rob her of the calculation abilities she normally
possessed—something like pain, exhaustion, or confusion—she would no longer be able
to use it.
The road fragments only closed a few millimeters, but her ankle spasmed in agony
nonetheless.
(Ah...gh...gah...!?)
She could flee immediately if she teleported, but her fear was overriding rational thought.

- Toaru Majutsu no Index Volume 6, Between the Lines 1