Many people call these Devilish children Devils out of confusion. The rulebook, in fact, makes this mistake. You can use either term interchangeably, they behave the same mechanically in my game.
The underworld is ruled by the venerable King of Devils, Malzorath--the Warden of the Damned. The workings of Malzorath's Underworld are shrouded in enigma, revealed only in part by the shadowy Liberty Mission housed in many large cities. What is of certainty is that Malzorath's subordinates which serve as jailers of the damned are corrupted or rebellious celestials known as Devils.
In recent centuries these devils are seen more and more 'above ground'. In some cities officials have granted Devils, for one reason or another, permanent residence in the form of the self-titled Liberty Mission. At these offices any person who enters may interact with honest-to-hell Devils with tiles like "Broker" and "Soul Care Advocate". These fiends are conniving servants to their powerful Archdevil ('Executives') drumming up souls in exchange for powerful magic solutions beyond mortal reach. Of these devils some are marooned ('independent practice') and others stationed on Initia by their superiors ('market pioneers'). To the folk that live near such places, they are simple business men of another race while others claim they are evil incarnate. Rarely will you find an opinion in between.
Devilkin, however, are not devils of this kind. Though they may 'practice' the family trade with the Mission they are not from the Underworld nor are they likely to have ever been there. Rather, these creatures are only descendants of the real deal--infused and forever marked one way or another, perhaps through red hued skin, horns, or even wings. How, exactly, one would end up in bed with a true Devil to have such a child is oft shared only in whispers and behind Mission doors, but one imagines the same reasons anyone wants for anything; power, fame, or fortune. Regardless of the reason, these kin resemble their fiendish parents and carry the reputation of such everywhere they go, often indistinguishable from their ancestors.
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