Nyx, are you feeling unseen because you would like the terms of your relationship to be based on the two of you? And not previous/other arrangements?
It sounds like Legion is used to and needs a certain kind of freedom. And it sounds like the terms of that freedom doesn't work for Nyx.
Is there something that Legion can say or do to you, Nyx, that would help you feel valued? I'm wondering if there's some kind of compromise that would both allow Legion the freedom he needs and the reassurance/communication that Nyx needs?
My heart is too big to fit into one person.