Parental Hypocrisy: The moment when Gilgamesh jumps in to play corrida with what amounts to a small locomotive with legs and arms, giving his father time to analyze its structure. Klaus roars at him for taking an unnecessary risk, but Jägermonsters eagerly express approval when they see a Badass performance, so right at the next page a Jäger sergeant quietly tells Gil that Klaus himself "doz crazy schtupid sctoff like dot all de time." Of course, as they both are mad scientists with chronic anti-hero syndrome, it wasn't likely to be the craziest for either.
The Baron stops in the middle of chasing Agatha just to make sure Zulenna gets revived (DuPree stabbed her when she was defending Agatha). When questioned, he bluntly states that it was his fault, and that the girl didn't deserve to die. He has several other moments like this, to demonstrate that even though he's a major antagonist, he is still a good man.
Lucrezia does seem rather fond of her nephew DuMedd... at first.
After Agatha drinks from the Dyne (when Higgs offers a cup of "water" to her.) She stops it before she explodes, however, by channeling the extra energy into the dying Gil and Tarvek, revitalizing them in the process.
After Zola downs a vial of Movit#11, which is basically a supercharged energy drink, Violetta's solution to stop the rampage is to inject her with more Movit#11, which will apparently lead to a complete nervous collapse (or possibly cause her to combust).
Plot Armor: While named characters do die, it's still a rare occurrence, compared to the casualty rate of the Mooks. To show that this is not due to the characters following the What Measure Is a Mook? trope, they often try but fail to kill their significant enemies. It's become a minor Running Gag for characters to complain their gun pulls to the left just after they only wounded their opponent with it.
Agatha's possession by the Other is set up as a big secret that could cause all sorts of problems, but Zeetha goes out of her way to mention it to Gil at the very first opportunity. However, Klaus is not aware of the true situation, and is unlikely to be willing to talk about it now that he's been wasped, and knows that talking would allow her to control him.
Subverted again, and significantly, here. Dimo has just informed the Jägergenerals and Klaus's leadership about the situation, which will presumably reach Klaus's ears presently. Whether they believe him remains to be seen.
Agatha: I believe another forty-five point three seconds, and I would have exploded or something. [...] Oh, yeah... I have got to try that again!
Power Limiter: The Heterodyne locket Barry gives Agatha is meant to subdue her sparkyness. She eventually outgrows this, and the locket has found a new use in keeping the Other contained.
The Power of Love: A minor case — at one point when Agatha is under the control of the Other, it becomes obvious that Gil will die without her help. So Agatha shrugs off the possession long enough to get the locket (mentioned above) on.
Lucrezia seems well aware of the possibilities inherent in her mind control devices.
Back on Sparks in general, Sparks, especially in places like Mechanicsburg, can practically take over someone's mind with their voice and not a lot else (strong-willed humans can resist it, but some people are just "natural minions".) Easy access to minions, the uses of the control voice, and the "tools" a Spark can make....
Gil: It looks like a toaster. Agatha: ... well, it is a toaster. Sort of. Gil: Sort of? Agatha: Oh yes. It could toast the whole town.
Proud Warrior Race Guy: The Jägers in general, with varying degrees of "proud" and "warrior" for individuals. For example, when Boris beats the crap out of a Jäger messenger to find out where the generals were meeting, their response was surprise and respect, saying that he'd "earned" the right to talk with them. Also, they take their oath of loyalty very seriously. General Goomblast even explains that the reason the Jägers hate the Other's bugs is that they force people to obey.
Punny Name: Doubling as Bilingual Bonus. Dr. Beetle's first name, "Tarsus", is the insect equivalent of the foot. Not a particularly meaningful pun, but it's there.
Puppeteer Parasite: Slaver wasps. Early versions just turned people into mindless revenants. Later versions could create sleeper agents who behaved otherwise normally unless given a command by the Other. The latest version can even infest Sparks, who were otherwise immune due to drastically different mental states from normal people.
Quote Mine: Agatha's recorded message that Lucrezia Mongfish is the Other and that someone should warn Baron Wulfenbach ends up being edited to say that Baron Wulfenbach is the Other. Needless to say, this causes problems.
Reed Richards Is Useless: The occasional machine gun isseen (actually some variety of Gatling, in most cases), but this weapon and the enormous amounts of dakka it can provide seem not to have changed the face of war as they have in Real Life. Machine guns become less effective when half the opposing army is made of metal, is using advanced Spark technology, or are Jägers.
Retcon: These pages. 12 Look at Sergeant Scorp's hat at in the bottom panel of page one, and then in the first panel of page 2. See the change? Standard Wulfenbach wings change to Vespiary Squad wings.
Retired Badass: An old Mechanicsburg sandwich-maker shows up in one of the side stories. He is nicknamed "Old Man Death" — by the Jägers. Turns out he used to run with them back in his youth — and never lost a fight. He still can forcibly boot one out of his shop now, leading to the "three tries" rule.
Right Behind Me: Agatha is too far away to hear the conversation, but still...
Xerxsephnia:[about Agatha] It's not as if she's in her own lab — or even her own town. She's kilometers from Mechanicsburg — trapped in our fortress — in the dead of winter. What can she do? [Agatha flies past the window behind her] Xerxsephnia: ... And why do you have that idiotic look on your face?
Romanticism Versus Enlightenment: A theme of the series is finding the balance between the two. With the Knights of Jove and Baron Wulfenbach representing the extreme sides of those movements.
Royal Blood: The House of Heterodyne and the line of the Storm King are both very important elements of the plot, as is resentment over the current overlord of the continent being a jumped-up baron.
Royal School: The baron's educational facility for Europa's heirs. The world makes it a bit different, and it's made abundantly clear its primary purpose is to keep the children of potential troublemakers firmly in the Baron's grasp, but the education is excellent and the faculty stern but fair and loving.
Tarvek's entire family—apparently, even the non-spark members. Best summarized by Tarvek when he explains that "The only way to keep my family in line would be to bury them in a row."
Sparks are, by definition, at least somewhat unbalanced; most recent ruling dynasties are sparks whose families shot their way to the throne at some point; and even if the one who first seized control of a domain were comparatively self-controlled rather than brilliant and/or charismatic enough to compensate for serious instability, their heirs can survive growing far more bonkers than those who have to worry about the typical Torches and Pitchforks thing.
Rummage Sale Reject: Appearances aren't very nonsensical for the trope, but the aesthetic is unmistakably present, mostly because several characters near-literally assemble their outfits this way.
Gil spends the latter part of his time in Mechanicsburg wearing an outfit from a bar's costume selection with most of the more ostentatious pieces taken off.
Krosp got his ubiquitous coat from a circus's costume department.
Jägers win their hats off of enemies, so if you're a Jäger and your hat matches your outfit, it's luck (and they prioritize nize hats, so many combine random aesthetics, such as Dimo's aviator cap with goggles and plume, in true "why not put all the toppings on the pizza!?" style).
Zeetha steals the long shirt and Badass Longcoat of one of Zola's Faceless Mooks and wears them under the leather pieces from her old outfit after all the cloth she was wearing is dissolved by mad science.
Moloch eventually ends up wearing the fancy red pants from the nice outfit he was introduced wearing, two shirts he must have obtained while imprisoned, a neckerchief to cover the collar/necklace all the Castle prisoners get, and a heavy apron from working in the murderous kitchen.
Othar yelling "Foul!" every time someone drops him from high up. Othar is the sort of fellow who thinks there should be rules to a fight, though it's pretty clear that the ones he has in mind are a bit laxer than those of the Marquis of Queensbury. He yells foul anytime someone ... well, he'd call it "pulls a dirty trick", but most everyone else would say "outsmarts him." Which is a lot, because while Othar is a first or at least close second rate spark (he wouldn't still be alive if he wasn't), he's also not that bright.
Burgermeister Zuken of Mechanicsburg's irrelevance.
At least somewhat, Gil's insistance on the fact that Beetle threw that bomb at him.
Sparks trying and failing to command their own creations: "that never works." Except when the creation is told that the Spark is not their master. Then it just wanders off in confusion.
When the Foglios have something to show you, they'll show you with an "Elegant and finely crafted link".
People are generally more likely to recognize Gilgamesh for his authority or power when he wears his "mighty nize hat".
Sailor's Ponytail: Airman Higgs ("The Unstoppable" Airshipman Higgs) wears one of these. As airship units are treated as analogous to naval ones (though seafaring definitely exists in this setting), it certainly qualifies as a Sailor's Ponytail.
Schizo Tech: And how. Telegraph, radio, telephone? Nope. Motor cars? Unheard of. Heavier-than-air aircraft? Two prototypes. Strong AI, lasers and resurrection are perfectly possible, though.
Lucrezia's lab has a brightly colored gumball machine with a small sign above labeled "Poison! - brought to you by the Illiteracy Reduction Campaign."
Science Hero: Damn near every spark that is not a homicidal lunatic and/or scheming manipulator... and frankly a couple who are.
Science Is Bad: All through the story and backstory, the most reckless applications of science are performed regularly by those most educated and talented at it. However, it's Played for Laughs often enough to parody the Aesop; when Science Is Really Bad, it's Crazy Awesome!
Science-Related Memetic Disorder: The Spark condition. Though even non-Spark scientists and engineers are a bit off-kilter, probably because that's how everyone expects them to act. Those usually have to assist or use stuff of Sparks. It's either become a Mad Scientist or go insane from this all anyway.
Secret Test of Character: When we first see Gil, his father is asking him to figure out what's wrong with the machine he ordered built — except he's really testing to see if Gil is honest (or brave) enough to tell him it isn't actually possible for it to work the way Klaus said it should.
Self-Deprecation: Phil Foglio's Author Avatar shows up at a hospital telling stories to sick kids... because they end up so bored that they easily fall asleep without the need for medication.
Self-Destruct Mechanism: Lucrezia's secret lab has one, and she activates it. The cancellation of self-destruct is double subverted.
Self-Serving Memory: When Castle Heterodyne attacks Castle Wulfenbach, Der Kestle has such a moment in response to Agatha's "When did I tell you to do that?!"
Seppuku: Expected of Jägers who break the Oath — but only if they get caught. At least if you believe Oggie and Maxim, who are admittedly clowning around a bit at the time. Otherwise, the Jägers show no aversion at all to rampant Loophole Abuse, such as by claiming that, being several floors underground, they're technically not in the town.
Serial Escalation: How many more "distractions" will Agatha, Gil and Tarvek go through before they reach their goal? The whole Castle Heterodyne arc appears to follow the old Hollywood maxim "start with a volcanic eruption, then build to a climax."
Serious Business: The Jägermonsters really love hats. Nothing more needs to be said.
In fact, Maxim refuses to let Lars be buried Hatless.
Shared Family Quirks: It's mentioned that Sparks' "styles" of design and technology run in families; Sparks born of Sparks, even when they're not raised by their parents, will tend to follow similar paths and designs.
Sharing a Body: Agatha and Lucrezia have had the antagonistic version of this relationship since the latter's mind was transferred into the former. It was supposed to be a Grand Theft Me, as mentioned above, but it wasn't totally successful.
Shirtless Scene: A fair number with Gil and Tarvek, and a few others (the Baron comes to mind). Tarvek did one long one wearing but a bedsheet, and Gil did a shorter scene wearing first just that, then... less. The battle of most skin exposed continues.
Shoot the Dog: Tarvek disabling and deactivating Anevka's clank. Wooster nearly does this to Klaus but is interrupted.
Side Bet: After Tarvek kisses Agatha after she saves him, the people of Mechanicsburg and the Jägers are seen placing bets on who Agatha will choose, with Vanamonde von Mekkahn and Violetta playing bookies.
General Zog: Ve haff a team of Jägerkin, Lackya, clenks and crew at each entry. Klaus Wulfenbach: Excellent. I'm pleased at the lack of rivalry. General Zog: Sir — dere iz a time to twit nancy-boy feetsmen und a time to crush bogs.
Tarvek in the same Twitter may have been a better example, since he sent Othar back and was much closer to the problem (while Othar metaphorically "slept through it").
Something Only They Would Say: Gil learns there are two alleged Heterodyne heirs in Mechanicsburg. One arrived in a gaudy pink airship, has made several speeches and then entered Castle Heterodyne. The other is in a coffee shop rebuilding their coffee machine (and causing several explosions in the process). It doesn't take him long to realize which one is Agatha.
Lucrezia!Zola: But he's been missing for years. He's no threat— [beat] [nervous glances] Lucrezia!Anevka: Do you want him to show up?! Lucrezia!Zola: Ooh... So sorry, dear. I can't think what came over me!
The Speechless: Punch ("Adam"). An early construct of the Heterodyne Brothers, he was unable to speak. Until Gil extensively repaired both Punch and Judy, granting Punch speech.
A couple of background characters are like this, apparently double amputees who use them as mobility prosthetics. Given that the whole backdrop is of a pseudo-Europe which has been in a state of low-level warfare for an indefinite period, It Makes Sense in Context.
Squick: An in-universe example of this is used by General Khrizhan to explain why Gil and Agatha being together is for the best: they can't exactly get their mad science on as long as the Other, Agatha's mother, is still inside Agatha's head and possibly sensate. Nobody will ever work as fast as those two will when they eventually twig on that. Incidentally, this also serves to keep the Unresolved Sexual Tension nice and unresolved, just the way the writers like it. Later the sentiment is expressed by Tarvek, to the Jäger Generals' amusement.
Squishy Wizard: Averted. For no explained reason, Sparks appear to be stronger, faster, better coordinated (okay, this one is more understandable), and tougher than any normal human. This isn't counting Sparks that may have modified themselves.
Steam Punk: Everywhere. The authors prefer to call it "gaslamp fantasy" though, because of the presence of Frankenstein-esque constructs, giant slugs that produce zombie-making wasps, resurrection procedures, death rays, and time travel. Also "calming pies".
Castle Heterodyne has several of these, including The Happy Fun Ball of Death and Fun-Sized Mobile Agony and Death Dispensers.
The Radio Theater Break has one, in the form of Ferretina's lightning generator, labeled "Zappy Fun Box MK 1."
Suddenly Voiced: Adam "Punch" Clay after Gil upgrades him during a resurrection. After several decades of not speaking, it's hard to make him stop again.
Super Serum: Many of them. Overdosing is always a concern, whether it's the Movit series of Smoke Knight pick-me-ups ("Drugs! Lovely, lovely drugs!"), the water of the river Dyne ("I LIKE IT!"), or the Jagerdraught and Battledraught brewed using the latter.
The Jägermonsters, who were created by the old "bad" Heterodynes as shock troops but then had to obey the "good" Heterodynes due to the oath of loyalty they take very seriously (though are still capable of breaking; look at Captain Vole). One of the ingredients of the Jägerbrau used to transform people into Jägers is water from the river Dyne, which Heterodynes are known for drinking and gaining superhuman strength as a result.
And Airman Higgs is looking mighty super, recently...
Super Speed: The various Moveit tonics, while not exactly granting super speed, give people temporarily increased speed and energy with some implied physical toll later on. Half a bottle of Moveit #6 got Tarvek on his feet for hours though he was fatally ill, and a few sips of Moveit #11 turned Zola from a reasonably good fighter into a crazy battle goddess.And then Airman Higgs shows us all what super speed really is.
Take Over the World: Baron Wulfenbach has already taken over the world — or at least the bulk of Europe, where the story is set — by the time the story starts, and he never wanted to. There's a conspiracy that seems to be trying to do this for themselves, using Tarvek as figurehead.
Agatha gives one to Martellus after he tells her that he performed an operation on them to make her physically addicted him (to the point of death if she isn't in contact) and that it can't be solved by killing him and hacking off an arm. Of course you'd think that Agatha would remember that this isn't a safe thing to do, but considering everything we've seen Martellus endure so far the danger probably isn't that great.
Tarvek: Ah! Violetta! My little cloud of doom! Even you cannot dampen my spirits right now.
Clank!Anveka tempts fate rather horribly only two pages after the Author Avatar's "Whelp, the day can't get any weirder!" above. Next page starts with Tarvek handing the device in question to The Other.
Clank!Anveka: Well, then. A device he doesn't know about- hidden where he will not find it — in a safe he cannot open? I have more pressing things to worry about. Besides, if it was in his hands, do you really think he'd just hand it to her?"
Xerxsephnia makes a very foolish assumption that she has Agatha helplessly grounded, far away from her town or any potential allies. When her brother tries to persuade her that "the Heterodyne Girl" is a threat after all, she brushes his concerns off, asking "What can she do?" Cue Agatha flying past the tower's window in a swan-shaped sleigh.
"The castle spoke to him. It demanded to be repaired. One of the team members spoke against the idea. And the castle made it clear that it wasn't a request. It was then that they realized just how far it was to the door."
The Madness Place: The trope namer, for good reason. All Sparks can be pretty crazy when they're in a "Spark-induced fugue state," as one character puts it delicately. They vary in their ability to control it, some being manically sociopathic and some retaining their ability to reason (to some degree). The most dangerous Sparks are by far the latter kind, since they can bend their madness to practical goals. It's not for no reason that Klaus, Gil, Agatha, and Tarvek, are among the most potent sparks in the setting.
Time Skip: One occurs when Tweedle takes Agatha (and inadvertently Krosp and Violetta) through a transit portal. Though it should have been instantaneous, two and a half years passed before they emerged. It's later revealed that Klaus caused this by activating some sort of time-stasis device in Mehanicsburg at the exact moment they entered the portal. Details are still scanty, but the Wulfenbach Empire reportedly longer exists, the territory around Mechanicsburg is under Gil's monomaniacal control and Tarvek's family has abandoned their claim to the title of Storm King.
Special mention goes to X the destroyer who decided a big X on the ground within range of enemy ordnance was a good place to set up his tent. Admittedly, it was inadvertent Schmuck Bait in that case...
Sure, Mechanicsburg is a great place to grab a pair of innocent hostages. Whom the pair promenading while the invaders are still surrendering should be.
Translation Convention: Word of God and incidental writing in the background says that everything is actually in German and Romanian, translated for the benefit of the audience. Except, one presumes, when we're privy to Wooster's thoughts as English is presumably still the language of Britain.
Trapped In Villainy/Explosive Leash: Tarvek's cousin, Tweedle, tries this on Agatha. Immediately subverted in that she knocks him unconscious, locks him in her chains, and sets about taking off the leash.
Traumatic Superpower Awakening: Sparks during the "breakthrough" usually go crazy in a destructive way. Due to her uncle's tampering, in Agatha's case the "awakening" part happened when she was technically asleep. It's explained also that this trope is how a lot of Sparks get killed early on: either their creation turns on them, or else they create an incredibly powerful weapon and yet are also still crazy/inexperienced enough to turn it on an army.
Trope Overdosed: Just look at the length of these pages. And it's still growing.