Nezrene [The Emerald] was a female Tholian who served as a weapons officer aboard the battlecruiser Lanz't Tholis in 2266. During that year her ship was captured by the Shedai Wanderer, and the crew enslaved. Nezrene was used along with 23 others as an element of the First Conduit. [2]
She was liberated by the Shedai Apostate, at the urging of Starfleet Ensign Vanessa Theriault and returned to her ship with the other survivors. Under her command the Lanz't Tholis protected the USS Sagittarius from a Klingon cruiser, allowing them both to escape. [2]
Some months later Nezrene defected, flying a ship to Starbase 47 to assist the Federation in their attempt to deal with the Shedai. She assisted Lieutenant Xiong in his research of Shedai technology. [1]