Phantasm Calculus

The Phantasm Calculus (幻結石,) or Illusion Calculus, is a calculus the produces illusions.

Appearance
Unlike the life calculus and nil calculus, the shape of the phantasm calculus is straight.

Background
It has been handed down in Yashima since ancient times.

Powers

 * Illusion: It allows Yashima to be invisible to the outside world and unrecognizable to them.