Shira Brie was an Emperor's hand, like Mara Jade she was assigned to kill Luke Skywalker, however she was assigned to kill him earlier than Mara Jade.  She was supposed to inflatrate the Rebel Alliance as X-Wing pilot, Major Brie.  On one Mission, in which Luke, "Major Brie", and a few others where trying to destroy an Imperial communications device in captured TIE fighters, Luke instictedly shot down Brie's ship.  What many would have believed to be the end of Shira Brie was only the begining of Lumiya.  Darth Vader's medics transformed her into the cyborg, Lumiya, dark lady of the Sith.  Lumiya became a new Emperor's Hand.  Not long before the Battle of Endor, she traveled to the planet Ziost to build the Sith weapon known as the Lightwhip.  But after returning she discovered both her masters had been killed.  After that she was on a constant search for Allies to help her kill the rebels who killed her masters, none of them lasted very long.  She has made random appearances around the galaxy, however her whereabouts during the Yuuzhan Vong invasion are an enigma.