Since we've started trying to give sides of ourself shapes and faces to better understand ourself lately, I wanted to come up with a description for everything that still remains undefined. the "grey spaces" between us, the messy bits of thought and personality that remain difficult to label or neatly categorize. thoughts that feel like they're coming from outside our sence of selves (particularly, a lot of the intrusive ones we get that are completely out of any of our systems of belief).
I think embodying Nebulous would likely be when we're blurry, disassociating, or otherwise not lining up with any facets we have an understanding of.
(though I will say, forms of dissassociation can also fall under Lunar & Umbral's wheelhouses as well. their sense of selves are both shaped by depersonalization / derealization in some way or another, at least in part)
(also, if anyone would like to: please feel free to ask us questions about our pluralishness/ selfhood whenever you would like. we've been feeling particularly chatty about it lately and would be happy to try and articulate things more clearly if any of this seems confusing)