Disruptive Wave

Disruptive Wave (originally DeMagic) is a recurring skill in the Dragon Quest series. Introduced in Dragon Quest III as a monster-exclusive attack, it nullifies all stat changes, such as those caused by buffs (Kabuff, Oomph) and debuffs (Kasap, Deceleratle).

It is typically known by major bosses and is practically required on final bosses, making the use of stat changing moves futile in such battles if one's luck is unrelentingly bad.

Dragon Quest VIII

Used by most of the later story bosses, starting with Dhoulmagus.

Dragon Quest IX

This isn't used as heavily by the story bosses (only King Godwyn and Corvus uses it). However, several of the grotto bosses and all the legacy bosses will use this ability.

It is worth noting that Disruptive Wave acts slightly different in this installment as it now only affects the opposition. This makes debuffs viable against many bosses since they can't use the ability to clear them away. The player can now use this ability against opponents, provided they invest at least 42 skill points in the sage's "Enlightenment" skill tree. This ability only costs 10 MP to cast.