A formidable enemy that, in addition to using powerful magic attacks, will also use an instant KO attack after a number of turns have elapsed.
While the two tonberries constantly healing the master tonberry and dishing out MP-absorbing attacks can be rather troublesome, if they are taken down first, the master tonberry's attacks will grow far more powerful.
Dealing wind-elemental damage for two consecutive turns will stave off the master tonberry's instant KO attack—a weakness which should be taken advantage of.
Attacks intended for demon-type enemies should prove quite effective.