Zendarin Windrunner

Zendarin Windrunner  was the blood elf cousin of the Windrunner sisters, who allied himself with the black dragon Sinestra in an attempt to create the twilight dragonflight.

Nexus Point
Zzeraku was the only survivor after Malygos absorbed Zzeraku's nether dragon bretheren. Berating himself for not trusting Tyrygosa's warnings, Zzeraku tried to seek out Tyrygosa's council on what to do next but as he roamed Azeroth, he was eventually captured by Zendarin Windrunner, who trapped him in Balacgos's Bane. Zendarin delivered the dragon to his mistress Sinthria. Sintharia, now calling herself Sinestra, little by little fed the nether dragon to her newest creation, the twilight dragon Dargonax.

Night of the Dragon
As a child Zendarin dreamed of rising among the ranks of the high elves, and become a strong and powerful noble. Like his cousin Vereesa, he never did truly fit the mold of high elf society, but he still sought to accomplish these goals through honest means. When the Sunwell was destroyed, Zendarin's hunger for magic caused him to embrace the technique of mana draining. As a blood elf, he became focused on one thing: gain more magical power to satiate his addiction and also to strengthen himself so that he may take more power from others. Zendarin eventually gained a notorious reputation for his unseemly deeds.

Zendarin and a group of drakonid attacked Rom and his dwarven group who were interrogating a skardyn. They fled after a roar of a dragon.

Zendarin unsuccessfully tried to kidnap Rhonin and Vereesa's twin sons, Galadin and Giramar, because he thought the offspring of a high elf and a human wizard would be powerful. Zendarin despised humans, thinking them as little more than animals, and didn't have a much higher opinion of Vereesa (and likely also of Alleria), who had married and had children with a human.

Though Zendarin helped Sinestra create the twilight flight in the promise of being shown new sources of magical energy to sate his addiction, he had his own reasons for allying with her: he secretly wished to take control of Dargonax as a magic source and his own personal dragon, and tried to do so with a final feeding to make him his slave. Sinestra had foreseen all however, and simply made Zendarin's betrayal a part of her plans, which resulted in his failure and escape from the hungry twilight dragon. Zendarin then sought to steal the Demon Soul (possibly as an alternate magic source having failed to take Dargonax, or as a secondary objective), the foul creation of Deathwing that had been destroyed by Rhonin years earlier. He would have pulled it off if not for Vereesa's intervention, which resulted in the destruction of the Demon Soul - and of Zendarin himself - when the stolen staff of the naaru touched the artifact.

Speculation
As a mage, he may have been a member of the Magisters.