Gamma Ray Burst

Gamma Ray Burst is a powerful bonus spell that can be obtained with one bonus point.

Appearance
Even though is called gamma ray -highest frequency waves on the electromagnetic spectrum (300 EHz)- and should be invisible for humans, both Sherry and Rutina (which were on the rear at the time the spell was casted) stated that the rear turned bright and "flashed dazzlingly". On the other hand, from the Michio's point of view there room was just "slightly brighter".

Description
Powerful enough to one-shot kill a 23rd floor monster. However the amount of MP consumed is even larger than with Meteor Crash, both described by Michio as MP inefficient.

Trivia

 * Michio's first time attempt ended without the spell activating due to his lack of MP required.