Mocax

Mocax is an old ally of Kakamu, and has been in and out of his service ever since he was taken from his home of Karda Nui by the Brotherhood of Makuta. They were separated following the destruction of the Matoran Universe, but later reunited when Kakamu was brought aboard Chocoman's base. Since then, Mocax has appeared to align himself with the Kestora and has separated from Kakamu's family.

History
Mocax was created as one of the Av-Matoran to inhabit the Southern Continent a very long time ago. He was part of the group who migrated to Karda Nui, and lived there with his kin until the Brotherhood of Makuta invaded. He was captured and mutated by Makuta Mutran, gaining an extra pair of arms on his back, but Mutran forgot to drain his natural light energy. When he was distracted with his other experiments, Mocax broke free and fled to the swamp below before being found by Kakamu. Kakamu saw no need to hand Mocax back over to his captor, so he gave him the opportunity to become his assistant back on Nynrah instead. Mocax accepted and swore loyalty to Kakamu then and there, and they left shortly after.

When the Battle of Zev's HQ was initiated, Mocax fought on the Brotherhood's behalf but was severely injured in the conflict. Ignoring the nonchalant attitudes of the other Makuta, Kakamu insisted on saving his assistant's life, so he restored him to full health with a variety of formulas he had created back at his lab. Despite this, Kakamu put his assistant in harm's way again some time later by ordering him to retrieve a Nektann power core on Zakaz. At this time, the Toa-Skakdi War was raging, so Mocax had to avoid aggressors from both sides. After snatching the core, he attempted to steal a boat to escape the island, but was stopped by Toa Rabot. Mocax kicked him back in an impressive display of strength and engaged him in close-ranged combat, but eventually lost the battle due to his lack of elemental powers. He was captured by Rabot as a prisoner of war, but escaped through his own resourcefulness. After journeying to Destral instead of Nynrah, he lingered for a bit tampering with motorbikes.

When Blackout took the contents of Destral onto Darkmount, Mocax was transported onto Darkmount too. Following Darkmount's destruction, he was rescued by Chocoman, who hired him to help build his base. By this time thousands of years had passed, so when Kakamu found the base, he was astonished at seeing his old assistant again. Mocax left his job to travel with Kakamu's family, which he did do for a while (but laid low during the Uterio War). After the war, when Kakamu was framed and went into hiding, Mocax went with him and his family to make a new life for themselves on a faraway planet.

Several years later, when Kakamu's search for answers about the Kestora brought him to the Red Star, he found that Mocax was already there. Mocax told Kakamu over transmission that he has the wrong idea about the Kestora and that he is going to bring Kakamu inside the star to talk to him there. What happened to Mocax after that is unknown.

Trivia

 * Mocax was originally a MOC built by Kon out of the spare pieces of Makuta Spiriah. He posted the instructions for Mocax on Brickshelf, if you want them, ask him.
 * You can probably tell how Mocax got his name. Kon was even more original back then.
 * Mocax was, possibly, the third character that Kon created in the RPG. The first two were Kakamu and the Savant.