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.
Same goes for child-Cyclonis, since all we see of her is a picture. She was smiling, but was that supposed to imply that she Used to Be a Sweet Kid, or was she a Creepy Child seen in a happy moment? Heck, even the doll she was holding could be seen both as a ragged, well-loved toy and a voodoo-ish looking thing.
Evil Is Cool: The Dark Ace is virtually unstoppable in battle except against Aerrow, and Master Cyclonis is able to take on all the Storm Hawks and the Condor's security systems in "Five Days".
Evil Is Sexy: The Dark Ace, Master Cyclonis, Repton, and Ravess of course!
Fanon: It's never stated that Lightning Strike is Aerrow's father, but taking into account Lightning Strike's supposed age, how much they look alike, and Aerrow's status as an orphan, it's highly unlikely they'd be related in any other way.
Piper and... well, anyone female. But special mention goes to Starling for whom Piper has what can only be called a girl-crush on. As for Piper and Master Cyclonis, tasting cream off of your female opponent's cheek and saying it left a "sour aftertaste" isn't gay at ALL....
Speak for yourself. This troper nearly had a heart attack when that happened. Also, the fight scene in episode six SCREAMED of rape.
Cyclonis sure had a phallic-looking staff, pulsating with energy...
Inferred Holocaust: The Nightcrawlers are implied to have killed the entire indigenous population of Terra Tropica because they might have interfered. Cyclonis also destroys nine terras in as many days during the series finale, which realistically would have killed a good number of people even with the Sky Knights trying to rescue their residents.
It seems that the creators noticed this, as later on, after she was identified by name in an episode they would mostly stick to feminine pronouns if she was mentioned again. It was made all the more confusing when you realize that Cyclonis is described as very young, and so could be a boy whose voice hasn't dropped yet (until they specify). This arguably makes her creepier.
Spitz sometimes gets this, being by far the smallest and skinniest Raptor.
Villain Decay: The Dark Ace goes to a credible threat and rival to Aerrow in the first few episodes to being unable to defeat him at 50 times his normal strength halfway through the series.
The only villains to not decay over the course of the series are Master Cyclonis, and the ones who started out as jokes anyway.