This npc is not available in game.
This is the original, The Burning Crusade NPC ID for Archmage Alturus. He dealt with the quests involving unlocking Karazhan and Nightbane. It was replaced with Archmage Alturus in Patch 7.1.0 in the Legion expansion.
For more information, please visit Wowpedia: Archmage Alturus.