I think that the Kal after getting all of the Nuva symbols, will go free the Bahrag and Bohrok. The go and try to ddestroy Mata-Nui. But since the Toa are powerless, the island is going to be destroyrd. But wait! It's the Toa of Light! Then (SPOILER!!!)
Takua destroys the Bahrag and the remaing Bohrok, the gets the Nuva symbols boack from the Kal and destroys the Kal.