Mask of Rahi Control

"Summoning the power of his Mask of Rahi Control, he touched the mind of a massive Rahi dwelling in the Archives not far below. In response, a huge claw smashed its way through the pavement and grabbed Nuparu. "Let him go!" shouted Toa Hahli, blasting Kualus with a powerful jet of water. Even as he staggered from the impact, Kualus realized what was about to happen. The creature had been roused by his mask power, but his concentration was now broken. The Rahi was no longer under his control."

- Narration, Dwellers In Darkness

The Mask of Rahi Control was a Kanohi that gave its user the power to control one or more of any type of Rahi at once. Most Rahi cannot resist the affects of the mask's power, with the possible exceptions of Krahka and Keetongu. The Mask of Rahi Control's power is not nearly as effective on insects and insectoid Rahi as it is on all other types of animals.

Since it's been used by Toa of Ice, it's highly possible it has an eyepiece.

Example Usage
In Dwellers in Darkness, Kualus used his Mask of Rahi Control to summon a Rahi from the Archives to stop a fight. However, Hahli broke his concentration, releasing the Rahi from his control.

Great

 * Toa Hagah Kualus - Lost Kanohi when he became a Rahaga--since restored.