Who is James the Artist from Wizard's First Rule and what is their importance?

James the Artist is a slim, dark man with one hand. He is a talented artist in the court of Queen Milena. He is especially dangerous because a magical spell can only be cast in a language the victim can understand. However, since drawing is universal, James can cast a spell on anyone, no matter what language they speak. He draws a picture that casts a spell on Richard. Richard is barely able to erase the picture and change it to a man with one arm, reversing the spell.