Those armor things on his hands conceal dirtballs, stones, ice, or whatever element the Brakka nuva is. 
It has the power to create rocks, ice, fire, water, ect. at will. It has a transformation, which is like a panther. 
It's weakness: If someone pulls down on his armor, its belly will be its weak spot. Its transformation is best for evasion,
since it leaves him vulnerable.
So far, I've got the main storyline:

"After the defeat of Makuta, the mischievous monkeys called Brakas (see lexicon at bionicle.com) started acting strangely,
 and began grouping up in a spot in Lewahi near Kini Nui. And then, the villagers tools started to disappear,
 so Lewa Nuva began to investigate. Lewa found the Brakas, as they were digging with the stolen Matoran tools,
 and when he got down, there was a huge silver explosion. When he looked back, there were weird panther-like creatures.
 He tried to catch one, but he failed. Now, the toa must find the Brakka Nuva, as they are the only hope against the Rahi Har."