While I absolutely love the design of the frame itself - I personally think that it has too many edges to fit into the warframe universe.
If you look at frames like Rhino and Excalibur, there's a lot more curves going on in the armor, which is also obvious in Tenno architecture. Still - don't let this detract from your piece - it's an amazing piece of work, and I actually wouldn't mind seeing it in game
Too metallic, armor like. Warframes are more organic looking in nature. Really cool design and I'd love to something like that in the game, but it suffers from something a lot of original Warframe fanart concepts do. It's too metallic and armor like. Maybe try revising it to make it look more organic and rubbery or like plastic. It's a great piece and all but doesn't fit the general look of the Warframes. I still like it regardless, good job.