Akamai

Akamai is the Toa Kaita of Valor. He is made up of Tahu, Onua, and Pohatu. He wears the Kanohi Aki, Great Mask of Valor, which gives him the power of Shielding, Strength, and Speed. He controls the elements of fire, stone, and earth.

History
Akamai has only been formed once. When the Toa Mata went into Mangaia, they encountered the Manas, crab-like guardians of Makuta. They proved too hard to defeat separately, so the Toa fused. Tahu, Onua, and Pohatu into Akamai, Gali, Lewa, and Kopaka into Wairuha.

Akamai Nuva
If Tahu Nuva, Onua Nuva, and Pohatu Nuva fused, it is likely they would form Akamai Nuva, though Akamai Nuva has never been brought into being.