Wraiths are frightening beings that appear as little more than a rustle in the dark, a misplaced shadow — before striking out with ethereal claws at the target they have been summoned to assassinate. Wraiths like killing, just for killing's sake; this makes them some of the most dangerous and unpredictable of the lesser daedra. The first wraiths were born to Lilith and sired by Ba'al, so it should be no surprise that they combine her predatory nature with his mastery of shadow and deception.
Wraiths may be hired as assassins by mortals, but they are so unpredictable (they could kill half of your own people in the process of getting the job done) that they are rarely asked to do anything, except by another daedra. In the war between the Heavens and Hells they serve as behind-the-lines operatives; if they find themselves in the mortal world without a master to watch them, they usually follow their impulses, killing without respect to a larger strategy. Some of them do develop distinctive M.O.s, however, much like human serial killers.
Wraiths were responsible for the murder of most of the Metamor chapter of the Lothanasi during the Battle of Three Gates. Another wraith attempted to attack the refugees gathered in the Chapel during the Winter Assault, but it was opposed and driven off by Elvmere. Also during the Winter Assault, two Moranasi attempted to escape from Raven and Merai by turning into wraith form, but they were trapped and slain when Kyia lured them into a room where the walls glowed with light and there were no shadows available for them to use to escape through.