Look, you need to stop asking open-ended questions, especially ones that have no one true answer. You might as well ask "if there was an expensive bath, what would it be like?" It depends entirely on the context - on who's making it, on why, on what conditions it's intended to operate. You could write a hundred different variations on the concept. Instead of mining the thread for this sort of thing on an infinite loop of questions that contribute nothing of their own to the thread; come up with your own answer.
Explore ideas. Ignore the role of the Yozi in First Circles - hell, ignore the role of the demon prince. Keep in mind the difference between Malfeas and Berengiere, or between She Who Lives In Her Name and Octavian - sure, you can look at parts of the latter and go "oh, right, he's a Pyrian demon", but he's not just a clone of the Whispering Flame and his wants and desires are a personal pursuit of power.
Concentrate on the progenitor of your demon species, and ask yourself what their own goals and aesthetics and methods are, instead of treating them like mindless automaton extensions of their ultimate Greater Self. Then work from there.