Mechanically-speaking, Sylph in Pathfinder: Domain are identical to those found in the Pathfinder Advanced Race Guide p156. You can also find Racial Information on them on the d20pfSRD website.
XP Cost: 6,000
Tulun Sylphs: Quiet and contemplative the Sylph are foreigners from another world, and for many years struggled to fit in even in the magically-imbued lands of Kajir. Keeping mainly to themselves or in small groupings, the Sylph watched the others and learned, spending much of their time observing the ways of the various cultures that made up the peoples of the floating kingdom. Since then they have become among the most learned of the people of Kajir, and have gotten a reputation as being knowledgeable and patient. What many were not aware of, until they volunteered themselves as tacticians in times of war, was that they possess a spark of tenacity that threatens to become an all-consuming storm should their rage be loosed.
Place of Origin: The Sylph come from a dimension which possessed more air than earth, with lightning in the skies and storms on the horizon. In Tulun almost all Sylph reside in the magical kingdom of Kajir, those who do not succumb to wanderlust.