Blizzard has revealed at this year’s BlizzCon that The Necromancer will make its’ way to Diablo III.
The character type is a part of an update titled “Rise of the Necromancer” and requires both DIII and ‘Reaper of Souls’ expansion. If you already own the game for PS4 or XboxOne, both the original game and the expansion are available in “The Ultimate Evil” volume.
The Necromancer will arrive sometime in 2017. You can read more on the topic here.