Given the similarities between Nael Deus Darnus and Estinihogg's apparent new form I'm wondering if we might get some new information on what Nidhogg's resurrected form actually is. I've been noticing for a while now that Nidhogg is essentially a primal in every way that matters. His new body seems to be made of aether, he's taken Estinien as a tempered host. The only difference being that he appears to draw aether from the eyes (due to them apparently being a nigh limitless source of aether) instead of the environment.

My guess for the finale though is that we'll shatter the eyes somehow and release Estinien and Lahabrea at the same time.

I wonder if Midgardsormr will make an appearance though. Killing one of his children (again) would surely be worthy of comment from him...