I agree with you entirely on Gali. I regretted giving her that design halfway through doing so and have every intention to change it as soon as I finish Lewa.
I went back and redesigned the Kanohi (again) drawing their normal iterations and their human equivalents, giving them logical purpose and reference to the original mask design, though I didn't change the Pakari or the Kaukau, because they were already perfect. The Kakama has intakes on the side meant to take particles (e.g. ash, minerals, etcetera) and separate them from the oxygen. It also has a bandana-based pair of goggles which keeps the same pollutants out of the rest of the face. The Akaku has a hood and a bandana, the inside of each of which is lined with fur, there is an eyescope attached to the outside of the hood to allow for long range sight within snow. The Pakari has a simple bandana and mining goggles, meant only to assist with sight underground and to keep minerals from getting into face. The Kaukau has a pair of diving goggles, which allegedly assist in underwater sight, and an oxygen intake, which separates the hydrogen in the water from the oxygen, and disposes of the hydrogen as waste. The Hau has a light hood meant to minimize extra heat while still protecting the head from flame and attack, the illusion of a spoiler is created by the end of the hood being only slightly above the top of the goggles, which were made to similarly protect the eyes from the harsh, volcanic ash. As well as a mouthpiece with a similar system to those found in the Kakama. The Miru is a one-piece design, with cheek plating attached at the back of the head, and then going up to cover the forehead, where it has attached glass, the purpose of this rudimentary plating is to protect from the force of flying at high speeds, and to keep insects from entering into the eyes.
This is where I rant about my headcanon: If the matoran are like the children, the Turaga are like old guys, and the Toa are like adults, then the Toa Inika are the awkward years/teenagers, and the Toa Mahri are the adult versions of them.
