“Mantis Talons,” Kamakiri said under his breath and lifted his hands.
The nails on all ten of his fingers began to grow at an alarming rate. In no time they were nearly a foot long. These were no normal nails – they were fat and thick, and sharp as knives, becoming fit for use as weapons. When they were nearly two feet long, their growth finally subsided – but by then, each nail had assumed the form of a savage blade.

Katanagatari Omnibus 2, Page 30