Ice Shield

"Ice Shield" could refer to two things. It was the tool carried by the Bohrok Kohrak on Mata Nui. They could freeze absolutely anything, even flames, and were used in an attack on Ta-Koro. Toa Mata Kopaka also carried an Ice Shield, though it was bigger than the ones the Kohrak carried. His Ice Shield became even larger upon his being immersed in energized protodermis and becoming a Toa Nuva.