How do you get black wizard in final fantasy 1?

In the original Final Fantasy I, you can obtain the Black Wizard class by first choosing the Black Mage class when creating your character. After reaching level 30, a Black Mage can be promoted to a Black Wizard at the Temple of Fiends. You must have the necessary items, such as the Crown, to complete the promotion. Once promoted, your character will gain access to more powerful spells and enhanced stats.