Since there has clearly been some failure to properly communicate this on my part, I'll state it clearly here.
Combat with Nothing There is not an instant loss. It is currently significantly weakened in order to maintain its current level of humanity, and will not give that up unless it has absolutely no choice. Nothing There and X are equals physically right now, with the differing factors being X's EGO Gear and support from others against NT's stolen Magic.
Fighting is a viable option as long as you're smart about it.
Good to know if it comes down to it, but personally I'd like to avoid it so long as Diplomacy remains An Option.
That in mind, I think I have.... an idea. My brain screams that it is a bad one, but it might not be. Also this isn't fully thought out and me sort of just rambling my thoughts out onto the keyboard.
First, backpedal on the 'i could help make you human' comment. Claim it was insensitive and based on preconceived notions of what Nothing There was like in the facility. Back then she wasn't quite as knowledgeable, and it was wrong to assume she'd still be the same. We're going through a time of change, and change can be strange, scary, and unexpected.
Back then, she very much was struggling to get what she wanted, but here, now? Nothing There is for all intents and purposes, a child. A very powerful child trying to understand the world and how to fit in with those around her. She is absolutely a person. A human, even if she doesn't have the shape of one, or a full understanding of morals and societal expectations.
So she's a person. And she managed it by emulating others, which is impressive. But at this point, she's reached the limit of what she can learn via mimicry. As it stands, sure, she's a person, but nobody can really say what
kind of person. So now... Her next step should be to solidify herself. Learn what she wants to do and be now that she's 'won' her main battle. Like Nobody Is. Her Abberation succeeded, after all, so clearly they must have been asking the right questions, right?
Except I have no gods-damned idea how to get from here to there. Because of course I don't. Meme, help???