The Legend of Athua, Toa of Lava.
A Matoran legend, tells of a toa that came from long before the original six toa. The legend tells of a master of lava, living inside the Mangai Volcano. Once in a 10 years he would come out and silently walk among the matoran. The legend says that he would walk in to a matoran village and stand guard for many days, then walk away again, to the next village, silently. The tale told of he's sword, made from pure fire, it reminded a lot of the fire swords used by gladiators on Spherus Magna. The tale also tells that he would crawl out of the volcano at dawn, stand proudly until the sun stood up high. It is theorized that he had a lava powered jetpack, that he had traveled in between all the planets of bionicle. That is probably why he has the gladiator sword and the gladiatorial armor.