Diablo III expansion Reaper of Souls, Myriam Jahzia, a Mystic who grants two special services to the player: Enchanting and Transmogrifying.
Myriam is a member of the nomadic Vecin peoples who believe in a diety named the Allmother. It is believed among the Vecin that the Allmother grants their people "the Sight", a sixth sense which is particularly strong in Myriam.
Enchanting allows the player to choose a new effect for their item. They are given a list of properties with a range of effectiveness, and the item will be granted that new power (while removing the old one) with random effectiveness. Enchanted items become bound to the player and no longer tradeable.
Transmogrification is a more cosmetic service, in which Myriam can change the color and appearance of an item without sacrificing any of the items power. So, if you find a powerful pair of lime green boots but are reluctant to use them because they clash with everything, Myriam can fix that.
Gamers can read more about the Mystic on the official site.