What is Johann hiding? The martyr assassin.
I think Johann isn't Mr. Spider, but he is still doing some shady business by Marquis Machina.
My theory is Johann and Paola, the faceless but mentioned dhampir, are secret Machina’s agents/assassins, the ones who kill people for starting the Gévaudan Act for Machina's machination.
I know Johann being Mr. Spider is the most widespread theory, but I don’t think Johann fits in that group because all leader members are the top of their own faction; Lord Ruthver treats Mr. Spider as a peer, while Johann is just a young dhampire informant broker.
The Charlatan isn’t only evil in the VNC 's world after all.
So Johann can still so something horrible without be a charlatan’ member, and I think his shady business can be with Marchise Marchina.
I think the revelation of Machina being a woman archiviste made people a little blind around her past actions and treating her as a potential ally for protagonists when she is clearly on the neutral-evil side.
Machina is a politician, a senator, and an archiviste who survived their genocide.
We don’t know yet what/who exactly happened to the archiviste clan, except they were ripped off centuries ago, which I think is already a lie because, in complexity, the vampire race is just more or less 400 years old, so the math isn’t adding up, so I am inclined to believe the Senate is lying about the archivist timeline because they are the ones who purged them.
As vampires live in Altus, and if the church was able to reach it, they would exterminate all vampires, not just a small group of them.
The only thing humans really need from vampires is astermite finds only on Altus, until humans can’t conquest altus they need vampires, therefore killing archiviste clan doesn’t benefict the church at all.
But if archivistes were killed by the Senate, how did Marquis Machina become a senator/beastia? Is she a traitor to the archivist clan? Is he a political prisoner of the Senate?
Her automaton suit, who make her unidentified, could be a hint to the Man in the Iron Mask/L'Homme au Masque de Fer, an unidentified prisoner during the time of Louis XIV. Often thought of as a political prisoner.
Her actions in the manga show, indeed, she is minding her business.
She is responsible for creating the weapons that are supplied to Bourreau, child soldier slaves who she is entitled to use, as she says to Jeanne.
Marchina is hiding her identity as an archiviste while sitting at the table of power (the vampire senate).
Her friends are Teacher and Lord Ruthver, who are not good guys.
She also has a sexual relationship with Veronica, who is openly sadistic and racist, meaning sharing her values or not being bothered by them.
She almost executed the dhampir trio for messing with her astermite trade and territory; only because Dante was able to negotiate and fascinate her, the trio is alive.
And last, she is responsible for the Gevaudan beast act by copycating the murders of the beast.
Therefore, we can easily hypothesize Machina is doing some terrible plans behind the scenes.
Let's be real: Marquis doesn't really need dhampirs as her broker informants; she is, after all, an archiviste. She can just read the memory of people, plus an ancient vampire like her should already have informants.
The Shapeless count implies her bees do more than just collecting information.
The Real Purpose of Dante's Crew.
They aren't Machina's primary source of information; they are her smokescreen, Johann and faceless Paola are her secret agents.
Agents who aren’t controlled by the vampire senate, like bourreau.
In the last chapter Johann has slipped, calling all dhampir community members Dante's and Riche's family but not his own.
It might be guilty because it is hiding himself and the true purpose of the Dante’s crew.
This is unfortunately like in real life, where minorities are used by criminal organizations because they have few choices.
Dante and Beatrice are looking for earning a place in light, legally and safely, but Johann is doing the dirty work.
In fact, I always find it extremely significant that Johann isn’t named after Vigirl despite the dhampir trio being based on the Divine Comedy. Riche is Beatrice, the ideal. Dante is a traveler, but Johann?
Like he has never been part of a trio.
But strangely, there is a name that is associated with John as duo: Paul.
John and Paul = Johann and Paola.
Saints John and Paul were two brothers, Roman soldiers, saints and then martyrs who worked for the empire while hiding their Christian faith. They were killed secretly, and their bodies were hidden in their home, as they were too popular for their good deeds, so the Roman Senate knows killing them in public is a terrible idea.
During the meeting in Dhampir Safe House, a name but no face was dropped: Paola.
In the dhampir safe house, one of the children comments he will bring dinner to Paola, meaning she can’t come to the dinner. Was she hurt? Working? Disliking outsiders (Vanitas, Noe, and Domi).
Johann looks to him with a worried expression, strongly implying there is something wrong with Paola, and Johann and she share something privately.
So Machina covers the role of the Roman employer while her “saints” act in secret.
If I am right, Johann has ability to be a spy/assassin.
1) Johann isn’t new to violence. When Dante and Riche met him the first time, his shirt had some blood spots but no injuries. Machina guards used more force on him than other dhampirs after being captured.
2) During the flashback Johann had a long staff, probably, which he used as a weapon.
3) He is athletic enough to keep up with the mission; he also has good control of the battlefield. As in Gévaudan Act , he was able to capture several hunters by surprise with only a net pistol or by having sharp instincts.
4) Dante called him a protector, and he is not bothered by scary and graphic comments from Johann, knowing the dark side of his friend. We can see Johann often acts as the physical protector of the trio.
5) Johann can hide his feelings so perfectly that his friends don't have an idea he hates Noè's guts. Johann always acts polite and servile like a person who worked in hospitality for 12 hours and is near to murdering everyone in the room but needs a job, so they keep the perfect mask on.
This last personality trait would make an assassin/spy perfect, because they work in a stealthy way rather than a noisy one. An assassin doesn’t let anyone know they are after all.
But Johann's violence is hidden under smiles, but it is easily close to being triggered.
During the Gévaudan Act , Vanitas threatened the lives of Johann and Dante while Dante tried to calm down the situation, but Johann, the coward, promised Vanitas death. Vanitas doesn’t look impressed but he doesn’t underestimate Johann either. Vanitas has sharp instincts that identify Johann as a true menace.
But before this interaction, Jeanne and Johann presented each other.
Jeanne asks what Johann is; he answers, "A dhampir", in rather mocking tone than his usual, and Jeanne, the hellfire witch, sweats coldly.
Johann noticed immediately, and he tried to justify his intensity by saying he disliked staying away from Dante. When Dante arrived, he jumped and aggressively cuddled Dante in front of Jeanne and Vanitas. Johann adores Dante, and he is flamboyant, but this behavior after Jeanne's instinct put her on guard is suspicious, like Johann was trying to pass for helpless.
Especially because after this scene, Vanitas threatens Dante and Johann, and Johann is ready to kill Vanitas.
Might Johann be an archiviste?
Another possible factor that Johann might be a good assassin of Machina and her true secret assert is that, if like the utent @noes-pillow theorized, Johann might be a child of Archiviste because he has white eyes and purple eyes, both characteristics that are present in Noé and Machina.
In VNC the ability to read memory doesn’t depend on a world formula but on archiviste biology, so if dhampirs have fangs too, hypothetically a dhampir born from an archiviste would be able to see memories too.
If both hypotheses are correct, Johann would be the perfect spy for Machina; his ability can take secrets from Machina's enemies without her exposing herself.
Then Machina used Dante Broker Company as an excuse for how Machina has these information: "My dhampirs found it ."
This also explains why Machina needs a duo of assassins; during the memories, while drinking, the archiviste is completely vulnerable. They need to be protected, so Paola is the one who guards Johann while he steals information from their targets.
Being an archiviste put a lot of stress on Johann and his imposter syndrome around the Dhampir family.
Dhampirs are seen as an annoyance but not a danger. Being an archiviste but a red moon dhampir passing allows Johann not to be killed immediately but means a stressful life to keep lying for his safety.
It explains his negative opinion around Noé. Noè is privileged by his position as an adopted member of the De Sade family, blind to it.
While other archivistes were killed, survivors were enslaved or forced to do worse for living. Noè can preach about pacifism without understanding survival takes priority over it if the other part is actively trying to hurt you.
Noè's privilege is manifest in the diplomatic shield that allows him to abuse his physical power when his pacifism doesn’t work. In the second chapter we see Noè breaking the count's desk in a moment of rage, but Noè doesn’t face consequences for it.
It mirrors perfectly Johann leaving with Dante and Riche after Count Orlok gave them the ultimatum. Johann doesn’t hide his sarcasm, but he is forced to be polite and servile and accept the threat.
I think Johann might have lived with his vampire mother because he shows some vampiric behaviour; in the series, the vampires sometimes nuzzle/rub other people/animals, which makes sense after all, as vampires have superior noses, so smell is part of unwritten physical communication.
Johann does this continually with Dante or Riche nuzzling, but one time he did it on Noè Noè's shoulder johann was hurt. It starts with Johann nuzzling Murr than resting his face on Noè's shoulder.
In cat behaviour, a cat would rub itself on a stronger member of the group when it is hurt.
Notice Noè is confused, but he doesn’t remove Johann. Johann might hide his smell as an archiviste, but he still looks for comfort from pack members. Noè might have been able to feel Johann is part of archiveste clan on a physical level. This explains they are comfortable on a physical level despite not being close, but Johann still hates Noè.
Johann hates being around Noè because of his sheltered idealism/pacifism, especially around the vampire senate. What if Johann is literally a survivor of the purge? Which explains also his dislike around Jeanne.
While Jeanne isn't responsible of archivistes purge because she was sleeping, she is still a Bourreau, senate's weapon used during it.
His name might be a reference to John the Apostle, the one who wrote the Apocalypse.
What if Johann survived the Archiviste genocide/purge, amking him a witness of an apocalypse?
It is impossible to say without other information than her being quoted, but I think she might be N70.
Like @astamite theorizes chapter 69 might show Morue again, as number 69 is connected to Vanitas, so following this example, n70 can be the introduction of n70 with its Paola identity.
If Paola is a Moreu’s victim, it might also explain why Paola and Johan were able to copy the murders of the beast because her time in the lab horribly turned her into something else.
But I don’t think Machina forced Paola and Johann to work for her. In the Beast act, Johann was pissed off with Machina and situation, saying Johann shouldn’t bring Dante with him.
There is no fear, only annoyence. What if that man, Johann was angry with himself to bring in dante in Gévaudan because Johann already knew how much situation was a mess because he had been already there.
Dante struck a deal with Machina because she is bored; her conditions are clear, especially for what she can offer. For a survivor archivist and Morue's victim, Machina is someone who gives them tools for their goals (Johann revenging his clan and protecting the dhampire, Paola tracking down Morue) in exchange for being her agents.
I don’t think the main dhampirs are going to die in this act.
I strongly believe that Dante will cut Vanitas off from his life after Vanitas puts the dhampir useless in danger and some of the children will die as consequence.
Vanitas won’t only lose his true best friend and the possibility to access Machina, but Vanitas also wouldn’t know Johann and Paola use Vanitas to find the mole in the dhampir community without esposing themselves and then throw him under the bus.