Samus Is a Girl: When she first shadows Alek in an all-concealing outfit, he can't decide if she's male or female due to the combination of small size, agility, fearlessness, and strength. He decides that she must be a very acrobatic boy until Zaven says that she's his daughter.
Badass Boast: About the capabilities of his Goliath superweapon; it caused The Tunguska Event. It later comes out that this was untrue. Tesla kept the remains of the meteorite in his luggage to hide this fact.
Big Eater: He likes ordering lavish multi-course meals.
Mad Scientist: It's agreed by everyone that he's bonkers. Barlow wonders later if he might have genuinely believed Goliath would work.
Historical Villain Upgrade: The plans for his Death Ray bear fruit in this story. Though he's not evil, it does make him extremely dangerous. He does eventually decide to use it on Berlin, but Alek kills him and it comes out that it probably wouldn't have worked anyway.
Dull SurpriseDeliberately; it's useful for a diplomat to appear in control when there are shocking developments. She admits that her ability to maintain it is quite strained when Deryn reveals her gender.
"Nascient Fixation sounded vaguely sinister, even if it was something baby ducks did."
What, Exactly, Is His Job?: She's the Head of the London Zoo, which seems to give her diplomatic authority and her suggestions have force with Captain Hobbes—Deryn finds it all quite puzzling until Barlow points out that being a "zookeeper" in a Darwinist society means a lot more than finding room for a tiger habitat.