Assassin is a job only available for Viera in Final Fantasy Tactics Advance. It can be gained by mastering 1 Sniper ability and 2 Elementalist abilities. Assassins are the deadliest force that Tactics Advance has to offer, with dangerous instant-KO abilities and incomparable stat growth in all areas except HP.
This makes the Assassin class the absolute best class to level up for Viera, but be careful about their HP growth, since Assassins are almost always the first target of enemies because of their low health. A special treat to Assassins is that they can wield either Katanas or Greatbows in combat. When equipped with the Concentrate ability, Assassins are considered overpowered, because their instant kill abilities gain near perfect Accuracy.