The Toa Daxia were not normal Toa, in the sense that they were "bred", using the DNA of six Matoran that had recently been killed as part of an organized terror attack on Daxia by the Brotherhood of Makuta (they murdered one matoran of each element). The Order of Mata Nui managed to save them by genetically breeding Toa bodies from each of them. They then joined the Order, partly out of gratitude, and partly out of wanting to be part of the struggle against the Makuta.