The Windwalker is the secondary specialization class of the Acrobat, the other being the Tempest. Windwalkers improves their mobility and specialize in AoE damage and skills that involves tornados and hurricanes.
Windwalkers are mobile attackers. Windwalker is by far the fastest character in game. With the help of showtime ( skill that removes cooldown from her passive skills ) she can clear a dungeon or clear a group of mobs in a very quick manner. Compared to Tempest, the other class advancement, A windwalker needs proper positioning before actually initiating an attack since her advancement skills are inclined more into hitting multiple targets ( eg Rising Storm )