Tavelon raised his hand. "Well, Thestrals can only be seen by those who have seen death. According to the tale the Pervell brothers literally saw death. There's probably a link there." But everyone knew that thestrals were related to death. He wracked his mind, trying to think about the other parts of the wand.
"Oh, and the number 15 is the
Magic Constant of a magic square, or a 3 by 3. The mathematic thing. That probably has to do with it's lasting nature." It was a shot in the dark, as the math itself wasn't magical. Unless you bought into arithmancy, which Tavelon hadn't so far.