Mechanically-speaking, Shen’ari in Pathfinder: Domain are identical to Drow found in the Pathfinder Advanced Race Guide p102. You can also find Racial Information on them on the d20pfSRD website.
XP Cost: 14,000
Tulun Shen’ari: One of the three member races of the Mor-Denoch Elder Council, the Shen’ari are an offshoot of the citizens of the ancient Nimben’el Elven Empire. In a time long lost to legend, the people of Nimben’el saw their mighty Empire buckle under its own weight. Opinion was divided as to how to handle the situation: though many believed that ways need to be investigated to lower the impact the Empire was having on the world, just as many believed that the worlds resources should be used to bolster their need for expansion, and that the end justified the means. Debate sparked into argument, argument into aggression and eventually into conflict. A great civil war broke out between the two parties, the Nim’ari and the Shen’ari, which resulted in the Shen’ari people leaving the Empire before it could collapse in on itself, heading underground and forming their own civilisation. When they encountered the Duregar and Svifneblin tensions were high and again, conflict broke out. From those skirmishes though the Elder Council was born and Mor-Denoch, deep beneath the surface of the world, became a secret world power and suffered the least during the time of The Reckoning.
Place of Origin: For hundreds of thousands of years the Shen’ari have called the subterranean land of Mor-Denoch home. Possessing of a privileged position within society, it is only the truly adventurous who leave their homeland.