Naruto, from Ultima Underworld
The Avatar found him in the corridors of the seventh level of the Abyss in Ultima Underworld I. Naruto told the Avatar that there were many dangers in this level - dangers which had cost his friend his life. He revealed that in the remains there should be a key to a room, where an item (the Crown of Maze Navigation) could be found to pass Tyball's deadly maze.
Naruto also spoke of how Tyball was draining the mana in the area with the help of a magical orb, and how a piece of Orb Rock could destroy the orb, severely weakening Tyball. He added that friends of his that were thrown in Tyball's prison could know where to find the Orb Rock.
Later, he was rescued by Garamon, when the volcano erupted.