"Mages who weave illusion to overcome their foes."
Illusionist is a job in Final Fantasy Tactics A3 that uses magic to attack all enemies at once and is available to Humes and Nu Mou. Illusionists have great MP, Magic Defense and Magic growth, which compensates for low HP, Evade, Speed and Defense stats. Illusionists are best kept away from enemy attack, because their low HP will cause them to be KO'ed quite fast -- This is actually quite convenient, as their Magick doesn't need them to be anywhere near the targets to hit them with spells. To access this job, the mastery of two White Mage action abilities and four Black Mage action abilities are required.
The high cost of their skills means that an Illusionist should have the support of a Cannoneer, or someone who can give them MP restoring items. The Seer's Recharge skill will also prove useful, as well as Magick Frenzy, which allows the casting of Illusion spells and physical attacks to all foes hit by those spells. Also, the Halve MP Support ability that they can learn via the Luminous Robe helps greatly.