Ether only affects ether arts, which have a horizontal band on their icon in the Art Palette. While these arts might not deal as much damage as physical arts, they are often associated with dealing debuffs, many of which (such as Chill and Blaze) can deal large amount of damage at a time. In addition, ether arts are not affected by the caster or target's accuracy or evasion, allowing the attack to connect every time, although the target may resist the attack if it is high levelled enough. Ether arts are also not affected by Soul Read, making them especially helpful when fighting Telethia.