XereX is a member of the Intra, a now nearly extinct race, who is now used as a servant by Oraku. He made his first appearance in the TBTTRAH Series in chapter 297 of Aftermath, although this was his second chronological appearance, as he is the main villain in the Green Version of The Architect.
XereX was a member of the Intra, a war-farring race on the planet of Kyrell-3 before the events of The Architect. He was a military officer who helped the Intra in the huge civil war on Kyrell-3, becoming most famous for being the one behind the brilliant attack that destroyed Atra in one fell swoop. After defeating the Atra, he turned towards the other races, preparing to attack, when...
Little is known about this time period. What is known is that Brenmac, a member of the Toa Zehvor, landed on Planet Kyrell-3, managed to obtain a powerful artifact called "the Architect" and wiped out nearly the entire Intra race with it. XereX escaped the planet after failing in battle against Brenmac.
(More will be revealed when The Architect is released this summer)
After escaping the devastation of his race that Brenmac had administered, XereX began wandering the galaxy, looking for some way to devastate the Toa back. He ran into Oraku, who offered him the prospect of helping revive the Dark Lord using a complex system of alternate portals. XereX, realizing that the Dark Lord's revival would mean revenge(and utterly failing to comprehend that it would more than likely mean a horrible world for him), agreed. Oraku then backstabbed XereX(not literally), infusing him with Xenon, as there was still a small amount in existence in the galaxy, and led him to Planet Zyren, where he used XereX to "collect" the Zehvor from the house...
Because he is awesome- *Makuta of Comedy edit*