Ash

 causes skills to fail to activate at a 50% chance, reduces HIT by 50%, and causes other effects depending on the target:
 * On plant-type monsters, reduces DEF by 50%.
 * On water-type monsters, reduces ATK and Flee by 50%.
 * Fire-element attacks will deal 150% damage on targets with the status effect.

Abilities
The following abilities inflict :
 * Volcanic Ash

Cure
can be cured through the following methods:

Prevention
The following lists ways that can be prevented:

Patches

 * Patch (2014 Apr. 02)
 * In Siege and PVP area, the Volcanic Ash status is modified to be applied without enemy.
 * Ascended state of the Ash effect [When you suffer damage from a high speed damage, 1.5 times damage will be removed.]