He creates a magical simulacrum (clone) of himself and plays on Tristan's knowledge of him back in Carthak, where he was a "book-bound idiot." He explains to Daine that people who are Black robe mages study books and learn nothing practical.
He creates a magical duplicate (clone) of himself and utilizes Tristan's prior knowledge of him from Carthak, where he was considered an unintelligent bookworm. He informs Daine that Black robe mages are known for their focus on books and lack of practical skills.