A member of the Brotherhood of Makuta, Antroz was the leader of the Makuta team sent to Karda Nui.  Their mission was to turn all the Av-Matoran (Matoran of light) into Shadow Matoran.  That way there would be no more toa of light to contend with in the near future.  Antroz is a fierce and powerful warrior, but has some form of honor (he prefers to defeat his opponents on his own without resorting to cheating).  After the Makuta entered Karda Nui, they were exposed to the massive energy flash the Mask of Life gave off to save Mata Nui.  This flash left Antroz and his fellow Makuta permanently blind, so they have to rely on the Shadow Matoran to act as their eyes.  

Antroz and his fellow Makuta were destroyed during the massive energy storm which awakened Mata Nui from his comatic slumber.