I think I can agree with this statement... It's a fresh look and I love the style. It's very different then all the other Excaliber skins currently available which gives it a huge advantage. In fact I'd love to see this style in all the other warframes too

BUT... if the rules and structure of Tenogen have not changed since I last looked... DE will make the same comment of the that horn being attached in some way, even if it's only a small bit of flesh. The problem is that you would have to change the underlying structure of the warframe to make it work it, which is against the rules.

There's also the rule of looking like a another Faction TOO much and a detached, floating horn and also looks like a sentient? It's way over the line of emulation and it is a sentient. This however is a mater of opinion and interpretation of the "judges", and not myself.

idk, mag has a tennogen helmet with floaty bits. not as noticeable as the helmet but still. /shrug.

Absolutely RAD skin, if DE had better in house talent with rigging and modeling and wasn't lazy, this would be a great addition. For some reason they just refuse to work outside of very limited parameters but then we have long stretches of little content until something half baked comes out.
Anyway hope they work with you to make it acceptable.