Bionicle: Mask of Light (2003)

In the robotic Matoran tribe from the island of Mata Nui, which is protected by six powerful guardians known as the Toa. Two small Matorans--one a potentially heroic "herald" and the other a historian-witness called "chronicler"--find a sacred mask of light, suggesting the imminent of arrival of a seventh Toa. Identifying that mystery figure proves difficult, however, especially with the evil spirit of shadows, Makuta, attacking Matoran with serpentlike warriors called Rahkshi in a bid to possess the precious Mask of Light.