So backstory, he was a Okotoan trying to overthrow Makuta as he treated people unfairly so he tried killing him and getting out of power using politics but neither worked so he gave up. Soon after when he was walking he came across a mask at the center of the island. After putting it on he went through a strange transformation which made him powerful. Unfortunately the overwhelming brain waves sent him into a deep sleep. He awoke centuries later to find the toa had come and help them on their journey`s.
I haven`t thought of a name so could you please suggest one