Flauros is perhaps the clearest example of conditional danger in the entire Duke catalogue. The original text is direct: he gives true answers about all things past, present, and to come — but only if he has been commanded into a triangle. The grimoire states plainly that without this constraint, he will lie in all things and deceive and beguile the practitioner in any business they pursue with him.

This is not a warning about attitude or mood. It is a description of Flauros’s default operational state. He does not lie occasionally or when provoked. The text describes deception as his baseline when unconfined. The triangle is not a preference or a refinement of the ritual — it is the mechanism that produces truth rather than harm.

Inside the triangle, his scope expands considerably: he speaks about creation, the nature of divinity, his fellow fallen angels, and can destroy enemies through fire. Outside it, the practitioner receives plausible-sounding falsehoods from a spirit who appears as a man with fiery eyes and a terrible countenance — difficult to detect, easy to be misled by.

What separates Focalor from merely powerful Dukes is the structure of the original description. His listed abilities are: killing men, causing drowning, and destroying warships. These are not described as secondary capacities or optional powers. They are his primary function. The clarification that he does not cause harm when specifically directed by a summoner frames redirection as the exceptional state, not the norm.

This is the inverse of what people assume about ritual relationships: most practitioners imagine an entity that helps by default and can be turned toward harm if specifically directed. Focalor operates in the opposite configuration. The grimoire also notes that he once hoped to return to heaven after 1,000 years but was deceived — a detail that describes an entity operating under a sense of frustrated expectation, adding instability to his already dangerous profile.

His dominion over wind and sea means the consequences of losing control of a Focalor working are not limited to the ritual space. The Ars Goetia describes genuine elemental authority here, not metaphor.

Vepar is unusual among dangerous Dukes because the thing that makes him lethal is the same attribute that makes him potentially useful: he can inflict festering wounds that cause worms to breed in the bodies of men, killing within three days — and he can reverse the same condition instantly when asked. The problem is direction. Any working with Vepar that lacks absolute clarity about which state is being invoked carries inherent risk of applying the harmful rather than healing capacity.

The grimoire notes that the wounds he causes are specifically described as causing worm infestation — a historically resonant detail that in context describes corruption at the physical level. The three-day timeline for fatal outcome is unusually precise for a grimoire text, suggesting this is not rhetorical exaggeration but a specific warning drawn from the tradition’s experience of what happens when Vepar workings go wrong.

His secondary domain — guiding armed ships, creating storms and illusions of many vessels — makes him one of the more operationally flexible dangerous Dukes, but that flexibility also means more opportunities for protocol failure.

Berith represents a different threat profile than Flauros or Focalor. He is not primarily dangerous because he kills — his domain is knowledge and transformation. He is dangerous because the Ars Goetia and multiple secondary sources characterize him as a consistent liar whose manner of speech (clear, authoritative) is designed to prevent the practitioner from recognizing they are being deceived.

His connection to alchemy — specifically the transmutation of metals into gold — has made him one of the more sought-after Dukes in the tradition, particularly among those drawn to material workings. This is precisely the problem the grimoire anticipates: the promise of material gain creates motivation to overlook or rationalize warning signs. The Dictionnaire Infernal and later commentaries consistently note Berith as an entity whose apparent gifts should be viewed with extreme skepticism, as they often serve his agenda rather than the practitioner’s.

The red iconography throughout his description — red armor, red horse, golden crown — is consistent across manuscripts and likely encodes his association with ambition, blood, and the corrupting potential of desire.

Aim is one of the more overlooked dangerous Dukes because his secondary domain — making people witty and giving true answers about private matters — attracts practitioners interested in intellectual or informational workings. The primary domain is almost incidental-seeming at first reading: setting cities and castles on fire. But this framing underestimates what the original text is describing.

Unlike Focalor, whose fire-adjacent power involves wind and sea, Aim’s domain is specifically conflagration of human settlements. The firebrand he carries is functional, not symbolic. His triple-headed form — man, serpent, cat — has been interpreted across commentaries as encoding human intelligence (the man), ancient cunning (the serpent), and unpredictable behavior (the cat). His handsome appearance in the outer form is consistent with entities that use approachability as a mechanism.

The combination of plausible attractiveness, genuine knowledge gifts, and an active destructive capacity that requires no conditional trigger makes Aim a particularly unbalanced risk-reward proposition for most practitioners.

Valefor represents a third category of Duke danger that is entirely distinct from Flauros’s deception or Focalor’s direct lethality: the slow corruption through relationship. The grimoire describes him as speaking temptingly to practitioners, making thieves comfortable with and well-disposed toward each other — and ultimately leading them to the gallows. This is not metaphor in the medieval sense; it describes a process of normalization toward harmful behavior that escalates over time.

He commands only 10 legions — far fewer than Flauros (36) or Focalor (30) — which might suggest lower threat. But his mode of operation does not require force. He operates through gradual erosion of judgment and the warming of relationships that begin to feel benign or even helpful. The lion-and-donkey composite in his appearance has been read as encoding strength paired with foolishness: the practitioner’s strength being gradually converted into the donkey’s compliant submission.

Valefor is particularly relevant for those who approach the Goetia seeking a “familiar” relationship with a spirit rather than a strictly constrained evocation. His entire operational description is built around exactly that dynamic — and his documented outcome for practitioners who pursue it is destruction.

Zepar is dangerous in a way that is unlike any other Duke on this list: his power operates by compelling third parties rather than affecting the practitioner directly. The grimoire describes him as making women love men and bringing them together — language that in context describes overriding of autonomous will. The built-in consequence described in the original text is barrenness: those brought together through Zepar’s influence are described as becoming barren.

This is a structurally embedded cost, not a side effect of imperfect ritual. The outcome is described as part of what Zepar does, not what happens when something goes wrong. Any practitioner invoking him for love or desire workings is therefore invoking a spirit whose successful operation includes harmful consequences for the people involved — and for those compelled, has removed their capacity for choice.

The tradition around Zepar is also notable for consistently placing his image in red — red soldier, red armor — iconography shared with Berith, suggesting a tradition-level association between desire, coercion, and the color encoding of blood and ambition in the grimoire’s visual system.