The black mage is actually a race in Final Fantasy 9 instead of a job-like the other Final Fantasy games. Most black mages though are manufactured from the mist from the lifa tree -and are magician dolls mass-produced for war, but Vivi was not one of the evil ones, that were just taught to kill. Also most black mages only live a year but Vivi, I believe lived for 6 years. Vivi was a prototype black mage- and was home-made instead of mass produced. I would think though they could not have kids since they are manufactured ?