Scirocco. Does he genuinely believe that banded bats will turn into humans or is he a Well-Intentioned Extremist trying to protect bats shunned because of their bands with soothing lies? Or he is tricking other bats with his sound tricks for his own ends?
Cama Zotz. Is he an evil, ambitious god or is he Well-Intentioned Extremist who wants to reunite the living and the dead, and punish those who have wronged his subjects (bats)? Judging by the end of Firewing, it is a combination of both.
Goth is the chief servant of Cama Zotz, a mighty bat from South America who becomes the greatest nemesis to Shade. Having escaped captivity, Goth lures Shade into a fake friendship so he may consume Shade's entire colony, murdering others in the way and devouring a host of innocent bats. Upon being recaptured, Goth intends to cause mass murder and chaos with bombings as a sacrifice to his God, ending the series with several other murders and escaping to spread his dark lord's faith and unleash him on the world.
Cama Zotz himself is a demonic bat-god worshiped by the cannibalistic Vampyrum Spectrum, and the ultimate evil of the series. The creator of the Underworld, Zotz is the one behind all of Goth's atrocities, ordering him to commit slavery, genocide, and mass sacrifice. Zotz intends to extinguish the Sun and wipe out all life; enslaves the souls of the dead and denies them a proper afterlife; and punishes anyone who displeases him—even his devout followers—by eternally torturing them within his stomach.
Heartwarming Moment: In Firewing, this conversation between between Shade and his son, Griffin, just before Griffin returns to the World of the Living, making these the (almost) last words they speak to each other. Qualifies as a Tear Jerker and So Proud of You as well.
Griffin: But I wasn't brave! I'm not like you. I'm a coward.
Shade: No.
Griffin: I was always scared. Always.
Shade: That's right. Being scared but doing it anyway. That's brave.
Popular with Furries: Bat fans are fond of Silverwing for being one of the few bat-centric series.
Try reading the end of Firewing without crying. Just try.
Shade: I'm sorry, Marina.
Arguably a villainous one in Firewing. Goth trying to pull himself out of the mud so that he can meet his fate with dignity has been known to induce Alas, Poor Villain.
What Do You Mean, It's for Kids?: The book might be marketed to middle schoolers, but the series has scenes of cannibalism, ritual sacrifices, and suicide bombers.
Complete Monster: Goth is a giant cannibal bat from South America. Captured by humans, he's sent to lab in a North American city for study. After escaping the lab, Goth begins to kill owls and birds, which General Brutus blames on the Silverwing bats, causing him to persecute them. Killing an owl hunting the Silverwing bat Shade, to seemingly befriend Shade, Goth plots to have Shade lead him to his colony so he may devour them all. Shade discovers Goth's true intentions after finding the corpse of a Brightwing bat Goth had eaten. Later, Goth and his brother-in-law Throbb eat a coven of bats and take the metal bands they were wearing as trophies. When Shade and Goth are trapped in a mine, Shade suggests they work together to escape, but makes Goth promise to allow him and his friends to live, a promise Goth instantly reneges on when he is out of danger. Near the end of the series, Goth teams up with the wolves to take over the forest and goes on a killing spree against the owls to fulfill his part of this deal.
There are fans who also wonder about how Nocturna (who was only mentioned once) and Cama Zatz (who as well was mentioned in one episode) would have been depicted fully in the series.
Characters like Voxzaco, Cassiel, and Phoenix from the second and third books are also explored in fanfiction for the show, especially the middle one since the show's last episode implied that Shade was going to go off and find him. In fanfictions focusing on adapting Sunwing, Phoenix is given the Adaptational Early Appearance to give her more of a role in the story.
Fanon: Due to Goth and Throbb being brother in laws in the animated series, many fans have come to the conclusion that Goth might have a sister in this adaptation that would have been shown if they had gotten a second season.
What Do You Mean, It's for Kids?: This was a kids' show, but was based off a young adult novel, and there's pretty heavy themes such as death and racial persecution, plus "guano" is used as a stand-in word for "shit" at least once.
YMMV tropes from the graphic novel include:
Complete Monster: Goth is the prince of the Vampyrum Spectrum—carnivorous giant bats from South America—and a devout worshipper of the dark god Cama Zotz. Captured by humans, brought to North America, and marked with a metal band alongside his servant Throbb, Goth forces Throbb to help him escape and find a way south before winter; their predation on sapient birds and beasts leads to war being declared on the already-persecuted northern bats. Saving Shade Silverwing and Marina Brightwing from an owl, Goth pretends to befriend Shade while scheming to enslave the Silverwing colony as a limitless supply of meat and sacrifices. Exposed through Throbb's incompetence, Goth relentlessly pursues Shade and Marina, slaughtering a cult of human-worshipping bats and claiming their bands as trophies. Deciding to overwinter at the Silverwing hibernaculum while feasting on the sleeping bats, Goth sadistically mocks Shade and Marina's revulsion towards his and Throbb's cannibalism. Struck by lightning while torturing Shade, Goth swears revenge with the intent of committing genocide on the northern bats.
and guide them to targets using echolocation. This crosses over into "Not Making This Up" Disclaimer territory, as Oppel spends the afterword of the second book explaining the minutiae of Project X-Ray and why it failed in Real Life.