Behind Kanzaki flowed a dark river. By the time she noticed the black surface had shaken,
a water pillar had already risen, close to twenty meters tall. It was a giant hammer with
joints. The terrible weapon grazed the underground city’s ceiling, closing down on
Kanzaki’s head.
If she had had her hands full merely with Acqua’s other attacks, she wouldn’t be able to
deal with this one, and she’d die.
However...
A splitting sound rang out as their death match unfolded, and something near Kanzaki
gave off a glare.
The moment he saw it, seven slashing attacks had brutally sliced up the water hammer
approaching from behind, sending it back into the river.

It had been Nanasen, using her wires.
“...I’m surprised you would think this was my full strength.”
The instant her lips moved, the seven slashing attacks all converged on Acqua from
various directions, as though complementing the track of her katana.

- Toaru Majutsu no Index Volume 16, Chapter 3 Part 1