These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Epileptic Trees: It seems every male in Dragaera has been theorized to be Devera's father at some point. Word Of God — confirmed in Tiassa — says it's Kieron. The founder of the Dragaeran Empire. For obvious reasons, this made the speculation much, much worse.
Parody Sue: Quite a lot of fans see Aliera as this, as she has a lot of superficially Sue-like traits that are belied by her being a complete Jerkass. (Note that the Sue-ish tendency for other characters to fall madly in love with her for no particular reason is actually a key contributing factor in the destruction of the Empire in Five Hundred Years After.)
The Scrappy: Savn is seen this way by some of the fandom because the two books in which he's featured deviate to varying extents from using Vlad as a first person narrator. Because of this, it's never clarified to what extent he's ever cured.
A cameo appearance in Tiassa establishes that Savn's psyche has indeed been restored, at least enough to have a coherent conversation with Vlad and Sara.
Values Dissonance : While it's not a universal trait, a number of Dragaerans (at least the really powerful ones) have no compunction against causing the deaths of numerous people in order to achieve their goals and value the lives of their own class more than those of ordinary folk. For example, Aliera refers to her father as being "naughty" for his scheming which accidentally caused the destruction of the imperial capital. And Lady Teldra, a very sympathetic character, thinks of Morrolan's massacre of an entire village as being the actions of merely a somewhat immature and hot-headed Dragon (granted, she has loyalty to him as an employee and is unfailingly polite).
Chaotic Neutral: Teldra (a priestess, in addition to her other jobs) describes Verra as the embodiment of capriciousness.
Evil Is Cool: He seems to believe this, happily self-identifying as evil.