Sacred:Book of the Seraphim
There is one book in all of Ancaria that is extremely rare and a most interesting find. It is the Book of the Seraphim and can only be gotten if a player is playing the Seraphim character.
In the Oasis of Ahil'Tar, there is a quest giver named Gunther the Seer who had a vision of a nightmarish demon hanging out in the desert and would like the player to go check it out. If a player is playing any other class, the must simply go down there, kill the demon and his minions and then return to the Oasis to have a chat with Gunther for their reward.
However, if a player is playing a Seraphim, they will find another Seraphim in the pile of dead bodies. She is the same one they rescued previously near Bellevue. She will tell the player that "they lied" just before she dies. At which point, she will drop the book and what amounts to being the only lightsaber in the game.
The book is very interesting - if for no other reason than it tells the story of the origin of the Seraphim.