The Desderain is a secretive organization dwelling on the Abyss. Skilled in the arts of illusion and other methods of disguising themselves from the tanar'ri, the Desderain is charged with helping out those who need it on that plane. Though they all hate the tanar'ri for various reasons, they realize that striking any telling blow against them is unlikely at best. Thus, they devote themselves to impeding the demons by helping their potential victims, depriving them of their quarries, and other such methods of aid. However, members of the Desderain obviously must remain in hiding on the Abyss, emerging from the shadows only when necessary, as the tanar'ri loathe even such minor actions against their interest, killing any members on sight.
- The Planewalker's Handbook, pg. 15