Ignap

Ignap is the a tall mage found in Buccaneer's Den in Ultima IV. He warns the Avatar not to step into "those woods", as the dark side was there, and if the Avatar entered them, it woul seal the Avatar's doom, and evil would consume the hero.

Ultima V: Lazarus
In Ultima V: Lazarus, Ignap doesn't appear, but a book written by him does. The book, called "Ignap's Book of Wisdom", is a treatise on the nature of magic, and specifically on dark magic. In the book he wrote about his encounter with the Avatar in Ultima IV, and it was explained that "those woods" refered to dark magic. Enlor from Cove was looking for the book. A copy was in possesion of Daem in Buccaneer's Den, and another copy could be found at the Lycaeum.