Iden

The Kanohi Iden was the Mask of Spirit. It allowed the user to release their spirit. When in their spirit form, the user was undetectable, and their physical body went limp. A being could fly at great speeds while using this mask. The only beings who could see a being in their spirit form was an Elda or a Rode wearer, and the spirit could only communicate with beings wearing one of those masks.

When a being was in this spirit form, their body was vulnerable, as they had no way to protect their physical body. In Matoro's case, the other Toa Inika would protect his body from harm until he returned.

Also, in spirit form, a being could not do anything to affect the outside world. This included their Elemental Powers, as that required a union of the mind and body.

Wearers

 * Toa Inika Matoro