Novablade Theory: the Novablade is made from a star devourer dragon's tooth.
I was reminded of this theory by this post and decided to share it. So we don't know much about the Novablade, but we do have this quote and image:
"Ivory draconic brought death's bite, known ever forth as Novablade."
I think the wording here is interesting. Both "ivory" and "bite" are very strongly related to teeth, and of course, we have the word "draconic." The most notable thing about the Novablade is that it has the ability to make an immortal "no more"--whatever that means. In other words, it can take down a startouch elf in some capacity.
You know what else has that ability?
Star devourer dragons consume stars and the magic within. Now, this passage likely means actual stars and not startouch elves, but in Patience and Ripples, Aaravos refers to the two interchangeably, calling the other startouch elves "stars."
If the star devourer dragon can eat startouch elves, it's logical to assume that its teeth could be used to kill a startouch elf, or at least take some power away from one. The use of the word "draconic" really highlights this, as it can only really be referring to a handful of things. This could give some insight into how star devourer dragons work biologically: their teeth somehow kill a star(touch elf) and then they can consume the magical essence. Like a snake injecting venom into its prey.
Also interesting to note: the Novablade is probably named after supernovas, giant explosions of stars that create black holes. A supernova can shine brighter than a galaxy and can be seen from very far away. Star devourer dragons also, in a way, create changes in space that can be seen from far away (the stars in the night sky disappearing) and replace a star with darkness (just like a black hole). There is also a connection between them consuming the power of a star and a black hole consuming... Well, everything. They are decidedly less explosive than a supernova, but there is an organism there that absorbs the energy of the explosion and, likely, minimizes it.
Will this in any way affect the plot? Probably not. Is it still interesting to think about? To me, it is.