After Bastion attempted to connect Cerebro to his Prime Sentinel network, Cerebro escaped after gaining sentience and nanotech abilities. Cerebro decided that it needed a dream and therefore adapted its purpose on Xavier's dream of peaceful co-existence between man and mutant. Cerebro used its new nanotech abilities to take the form of Xaiver and to create its own team of X-Men; to capture, catalogue and store every last mutant. Each of these X-Men were created by picking and matching various powers, personalities and appearances of various mutants in Cerebro's database; each one also had false memories of a normal life but in reality were simply nanotech creations which were only "born" not too long ago.
The team's first mission was to kidnap the X-Man Kitty Pryde in order to use her computer skills to extract a virus from Cerebro's systems. They were successful although she escaped before she could be stored in cryogenics.
The team soon defeated the real X-Men in combat and believed them to be destroyed; their attentions soon turned to a government satellite created to detect and destroy all mutants from space. The team soon began their mission to destroy the satellite's nuclear reactor (despite the surrounding civilians) and use the satellite's tracking system in order to track down every mutant for capture and catalogue.
Although it seemed that Cerebro's X-Men were going to succeed in their task; it was not long until the real X-Men arrived to stop them. After their defeat and Cerebro's identity revealed the team regrouped in confidence that Cerebro would forgive them; Cerebro instead decided that it was nessercary to absorb its team into its body in order to gain enough strength to defeat the real X-Men, although not before expressing its feelings for them first.