Fourth wing theory :
Naolin is a venin, AND Brennan is also a wyvern
So everyone has heard the theory that naolin might be a venin bc of when he brought brennan back to life. And that in the process died bringing Brennan back.
Well I think that Brennan might be a wyvern of sorts. So it's not clear on HOW the wyvern are created; but I have an idea
I think that venin inbue an object with magic (eg rock) and then seal it with a rune. And then after that the wyvern is born after that.
Also, Brennan is described as having rune-shaped scars on his hands. And noalin is almost NEVER brought up
And because Brennan being a wvywen he is also unconsciously giving naolin all the info he needs.
This also explains why we see so little of Brennans dragon and why syaegl does not like Brennan
