I am newer to these boards, but I am a longtime fan of Bionicle. My main reason for entering these contests is that I feel that I’ve finally gotten to the point where I can do these characters justice with the skills I have. That being said, here’s my submission:
Mask (sketch):
Mask (color/ink):
Bionicle is a very interesting setting for me, because most of the cast are the results of alien but intentional design that I can take apart and figure out through drawing. Helryx, especially, is a character I like to wonder about since she has a very distinct origin - she’s uniquely what amounts to “a prototype Toa”, with her design informed to a degree by the Glatorian, her predecessors in a sense.
When I saw the winning MOC, I was struck with a bolt of inspiration and got to work. I did opt to have a little bit more of a divergence from the MOC in some respects, such as adding a bit of diversity to her colors to denote differences between certain part types (for instance, her muscles are blue-black and her hoses are dark grey.) I also went for a version of the body that incorporated elements of the MOC, but also looked more like a living machine.
The biggest train of thought I traveled down was about how Helryx’s immense age might manifest in a race of basically immortals. Unlike beings such as Artakha, she was likely never meant to live this long. She once looked just as splendid as any other Toa; but now she’s bent and withered in a way that could be seen as almost gruesome to other beings. Even her armor is missing in places, leaving her muscles exposed and gnarled in a way that most would find disturbing.
Her mask was based on a design I had already thought out. It’s made of simpler shapes as befitting of an older Toa, but there’s some nods to the Glatorian such as the engraved designs and head fins. Her “cheekbones” are also a wink to the idea of her as an old lady, and it also draws a bit from the 2001 Noble Masks.
Which led me to this final image. Looking at this now, I am very happy with the result - especially since I now realize that I’d subconsciously always visualized her this way. I opted to have a very fluent, comic-book style to the piece, and I think I did her justice. 
Thanks so much for your consideration!