Since the First Atlantis Reconnaissance Team changed the nanite base code from the Central data core on Asuras, some of them were able to take a different persona at will. That particular one chose to take the appearance of Radek Zelenka. He was supposedly part of what was left of Niam's faction and decided to leave Asuras, steal a Zero Point Module and built a copy of Atlantis, and manufacture nanite-based copies of Sheppard's team, to learn how to ascend, because her team wanted to find something called a "soul".
When a probe crashed on Atlantis, from Oberoth, Dr. Rodney McKay tried to tap into the base code. However, Zelenka secretly created a programme to destroy the probe's systems before McKay got to them, and covered up the whole thing by destroying the probe. However, the team eventually found out about this. However, the rest of the Asurans discovered the city attempted to destroy it. The team escaped, but all the Asurans, including him were most likely killed or destroyed in the process. (SGA: "This Mortal Coil")