Well, yes. He is, in a word, the human concept/want of/desire for self-destruction. It's why we've been so careful in dealing with the shards of him that show up to us, the thing is though... That's actually kind of what we're looking to do long term.
Establishing a new metaphysical frame-work for humanity (and others) to run off of. Likely to be a mix of motonic and magasutchi based physics in some way, since those are the ones we have access to. This will, effectively, erase humanity as it currently is, and thus fulfilling Nyarly's goal of self-destruction, while also letting humanity move on to a new form letting them keep existing. This time without Nyarly in the background. Hopefully.
Probably not though unfortunately. TED was there for Motonic physics, so that's 2 for 2 on having some Great Shadow exist. TED was pinned down in a way Nyarly just can't be though, so... *Shrug* Who knows.