A close associate of Sethra Lavode, and as it is believed that she is a Yendi, little can be fully explained about her. In fact Paarfi of Roundwood claims that no one has established her House with certainty, although Paarfi himself described a meeting between her and Pel that implies quite a bit. Morrolan explicitly identified her as a Yendi to Vlad as our favorite Jhereg was unraveling the conspiracy against Norathar. She is exceptionally tall, even for a Dragaeran, has an attractive face with light brown hair, and might easily be taken for an Athyra.
The Sorceress in Green is very old, for the first evidence of her activities surfaced several cycles previously to the restoration of the empire. This works out to well over 20,000 years, or approximately 7–10 times a normal Dragaeran lifespan. However, she uses sorcery to maintain her appearance at around a youthful 250 years of age.
Her fame as a sorceress dates at least to the fifteenth Tsalmoth Reign when she created the "Wall of Circling Winds" to hold back a tidal wave. Later, during the Littleshell War, she held the entire sorcerers' corps of Baron Niefivre at bay for three days, giving Sethra time to flank her opponent and win the war for the Empire. Her skill was regarded so highly that she was offered a command position in the Athyra Guard during the seventeenth Athyra Reign.
The Sorceress in Green was instrumental in the reconstruction of the Empire, serving in the Battle of Castle Black and Battle of Adrilankha. But she was also the key figure (and villain) in the events and conspiracy portrayed in Yendi. During that time, she is known to have pretended to be an Athyra, Baroness Tierella, for the purpose of establishing false evidence that Norathar e'Lanya was a crossbreed bastard, in an effort to ensure that Sethra the Younger would become Warlord.
Oh, by the way, she likes to wear green. In particular, a dark green similar to the color of the needles of evergreen trees.