These are very similar questions, so I'm putting them in one post.
1. We've only seen the Toa Nuva use Nuva masks, outside of the Legendary Vahi. Would they be able to use non-Nuva masks? If not, would they be weakened when wearing normal masks, like when not wearing any mask at all?
2. We know non-Nuva beings cannot use Nuva masks, but would they still be weakened as if they were not wearing a mask, if they were to wear a Nuva mask, say if a Helryx was to put on Pohatu's Kakama Nuva?
3. If a Turaga was to wear a Great Mask, would they be weakened as if not wearing a mask? Or would they simply be unable to use the mask, but sense that it's a Great mask, like Matoran can? I assume they wouldn't they be able to use it to the extent of it's noble variant?