A few years after the Order of Mata Nui was founded, they seemingly randomly discovered a single unique Matoran of a new element they dubbed 'Peace'. This Matoran of Peace was Nomi, and she was quickly recruited into the Order. The Order intended to study her one-of-a-kind abilities thoroughly before making extensive use of them. One of the peculiarities of the Toa of Peace was that they grew organic hair from their heads.

Nomi was almost instantly transformed into a Toa and added to the Toa Artakha to begin training to use her powers with Helryx. This training was apparently very frustrating for Helryx, as Nomi was not a quick learner.

Years later, Helryx and the Toa Artakha came to Mata Nui's aid during the Dimensional Relocation of Luna Magna, an incident started by Karzahni that caused a dimensional rift to be opened in space, which pulled the planet Luna Magna and thousands of powerful artifacts into the Prime Universe. 

Nomi assisted in collecting the many artifacts displaced by the incident, but unfortunately, was forced to sacrifice her life with a Nova Blast in order to generate a large enough barrier to contain Luna Magna, the rift, and the massive number of artifacts. Helryx was devastated by the loss of Nomi, believing her death to be her fault.

The Order of Mata Nui went on to discover three more Matoran of Peace, Haku, Ko, and Rei. Each Matoran was discovered consecutively only after their predecessors' demise, which greatly puzzled the Order.

Abilities & Tools

The Order of Mata Nui dubbed Nomi's abilities as the Element of Peace, but a better description of the power would be 'Barrier Manipulation.’ Referring to this ability as 'Peace' stuck, however.

The full extent of a Toa of Peace's abilities has never been defined, but studies done on Nomi and the other Toa of Peace discovered that they have control over anything that can be technically classified as a barrier, including Energy Barriers, Physical and Metaphysical Barriers, Spiritual, Magical, and Imaginary Barriers, and Quantum Barriers. 

Like all other members of the Order of Mata Nui, Nomi's mind was shielded from mental attack.

Nomi carried no traditional Toa tools or equipment, as she wasn't trained enough to use any before her demise.

Nomi wore a Kanohi Rau, the Noble Mask of Translation.

Personality

Nomi was quiet, and very kind. She never seemed to grasp how unique she was as the Toa of Peace, and would easily become overwhelmed by the expectations of the Order. During her time as a Toa, she was not a quick learner, which sometimes frustrated Helryx.

Trivia