Berthold

Berthold is a level 70 elite human ghost who provides information about the tower of Karazhan. He presides within the tower in the Gatehouse near the entrance. He also provides teleportation to Shade of Aran's room after this boss has been defeated.

Quotes
Greetings, travelers. I have been instructed to treat any bearer of a key to Karazhan as an honored guest of the Master. Feel free to ask any questions you wish of me. How may I assist you?


 * This is the tower of Karazhan and the residence of my master, Medivh. As a humble doorman, there is little else I can explain to you.


 * All inquiries regarding Medivh should be directed to Moroes, the Tower Steward. I myself know very little about the Master's business.  I believe several nobles are currently having an audience with Moroes in the Banquet Hall, if you wish to inquire further.


 * From here in the Gatehouse, you may travel in one of three directions. The stairs behind me lead to the Grand Ball Room, where guests are currently being entertained.  I'm sure you can smell the nearby Stables, and the entrance to Servant's Quarters [sic] lies next to the Gatehouse door.