Raven

No person has been known to meet the Guild Master. It is even said that that he is a myth or a she – or something else entirely. It is only guessed that there is a Guild Master at all. Known only as Raven, they have such a thrall over the common people of Tyr, that the name is only mentioned in hushed voices.
Guild members are selected by other members and invited. Usually an invite that is refused leads to death. Promising talent is spotted by existing members and in order to prevent future conflict, they are either enrolled or eradicated.
The Guild structure is mostly disparate and fluid. The location does not remain static long as most communication is done through codes left in secret places rather than face to face, so no-one knows everyone in the Guild.
The Guild is has in the past been associated strongly with the ShadowFell and members are believed to have the ability to disappear at will into the shadows – appearing at just the moment to deal the death blow to their target.
The Ravens seem to have been in Tyr for as long as Tyr has been in existence. It is improbable that only one has held the name of Raven, but what is not mistakable are the skills taught through their ranks. Almost utterly unique in the land of Athas, the Guild operates in such secrecy over their ability that few even suspect, believing it to be the work of magic or some otherworldly pact. How very close that is to the truth, many will never know.

Raven

Dark Sun: Seared to the bone pord pord