The Mystic is the Diablo III artisan who specializes in enchanting and modifying item properties.
The Mystic was introduced in Reaper of Souls. Her Enchanting service lets players replace one selected affix on an item with a new property, while her Transmogrification service changes an item’s appearance without changing its function. These systems separate appearance customization from equipment power.
The Blacksmith is the artisan associated with forging and salvaging equipment, while the Jeweler works with gems and sockets. Those roles are common sources of mix-ups because all three artisans improve a character’s gear, but they do so in different ways.
The Mystic’s role became especially useful for endgame gear, where a single unwanted property can matter greatly. Players can reroll one property, but the available results and costs depend on the item and the crafting materials used.