Xerxes was a member of the team of Sorreters who created kappa in 579. Not long after their creation, the creatures began causing trouble, which led to a self-imposed ban among Sorreters against creating either intelligent or dangerous mythical creatures. The team's next project, which was completed in 581, was the creation of the much more docile kitsune. However, Xerxes was never satisfied with smaller, safer projects, and secretly worked on his own side project, also in 581: he made creatures he called cyclopomonoceropegasoporphyranthropophagoi. (The shortened form is "CMPPAP," pronounced "sim-pap.") While these creatures possessed no intelligence, they were deemed far too dangerous, and in fact Xerxes was considered by many to have gone mad. There was talk of either banishing or imprisoning him, but before anyone could make up their minds what to do about his transgression, he fled Sorret and went into hiding.
In 600, it was discovered that he had created a race of ogres, in the Drop Lake Mountains. However, details of this discovery were covered up by the Sorreters who discovered it, so little is known about it. Over the centuries, there has been a fair amount of speculation; some people believe he used his ogres as an army, with the intention of world conquest. He was defeated by the Sorreters, but managed to evade capture. (After his defeat, Sorreters created chupacabra to hunt ogres and patrol the Drop Lake Mountains, but Xerxes himself was never found.) In 617, Xerxes apparently attempted a second conquest, having created an army of goblins. Again, the details remain sketchy, and we have but speculation to go on. However, it is known that Xerxes was killed at that time. (Some say he was killed by his own creations, rather than enemy Sorreters.)
While some believe hardly anyone other than Sorreters were aware of either conquest, others believe the first conquest was well known at the time (and subsequently covered up not only by Sorreters, but all the world's historians). They further believe that, rather than being defeated before he could do any real damage, Xerxes's first conquest in fact caused an estimated 10,000 deaths- even if the majority of them would have been Sorreters. This is one theory to explain a decrease in world population between 600 and 602, though most historians dispute the idea that such a war ever happened at all. To this day, there is no mention of either conquest in the history books of First Nation. However, there have supposedly been talks of including the rumored events in newer books to be published for schools in the United Villages of the Chaos and Sorret.