Greater Demoness only noticed her because of how her power was great but also could sense the unusualness of its aura. Succubus further elaborated later while holding her prisoner that the sensual aura had weakened and demanded to know why. This suggests that being more important than the power itself. It is also unusual that the greater demonoss hates humans but became out of characterly obsessed with the idea of owning Sparkle specifically. This definitely seems to suggest that they can feel her aura. You should probably also take time to notice this aura seems to cause every demoness she meets to suddenly start stalking her obsessively.
Regarding the prison scene with the succubus...
Tho succubi are inherently prone to carnal behavior, and while the succubus seems, *on the surface,* primarily concerned with Sparkle's servitude (the nature of which was never defined), she keeps circling back to the question of Sparkle's power, itself, and not obsessing over having sex with her on the spot, which is what an arousal buff would induce (tho a succ *might* actually have better impulse control, in that area).
Quite possibly even more tellingly, tho, she also brings up the question of where *Lel's* power "comes from". This, despite us seeing zero proof that Lel even *had* any power, up to that point.
Other than gender, Lel and Sparkle have one main thing in common (which shall not be mentioned here, for spoilers' sake), and it's not being a HealSlut, as Lel doesn't even have a class.
I suspect that, if Rudedude were to come along, the succubus and her boss might also sense a similar power in him.
Given the conversation we've seen, it seems like the succubus and her boss are vaguely aware there's something going on behind the scenes with both girls, something that involves a power coming *from somewhere else*, and they want in on it, or at least know what it is so they can deal with it.
Notice the question about Lel got cut off by Sparkle's incessant and inattentive rambling? This suggests it is a literary device used to alert *us* to the fact that this is a critical detail that Sparkle is missing.
Ofc, this is speculation based on what we've seen, and Davie could change it at any moment.
As to the passive aura effect..
It would make sense if it's a (presently minor) modifier on a RNG % chance. Because it's all a roll of the dice (probably on timers checking every X seconds), and with sexy outcomes at the faaaaar end of the scale, you would get completely unlikely, out-of-left-field stuff, like an obviously honorable guard suddenly wanting to sit on Sparkle's face, even while bandits usually choose to do nothing sex-oriented.
That last bit, though, is probably more the issue I am noticing: bad guys, even those noted IRL for *highly* antisocial behavior, are *not predisposed* to "go there".
The world they occupy seems mostly remarkably tame, likely due to the POO devs wanting to keep their game from getting slapped w/a "Mature" rating.
**Real-life** bandits are almost invariably *VERY* antisocial men (not at all likely to be women, for a lot of reasons, and absolutely rejected by society) ekeing out a meager existence at the edges of civilization, **with almost no access to women.** They are, from all accounts I've read or heard of, predisposed to abruptly take girls if they see them, quite probably non-consensually.
The POO devs are, in their (ironically named) MEGAREAL world, seemingly weeding out X-rated behaviors, so the HS class being unofficially and haphazardly tossed in there is going against the grain of the game, in putting such behaviors (back) in. Thus, the very unexpected lack of rapine frenzy in bandits that one would expect from the HS aura affecting them.
The one time I've seen heavily X scenes in the general population (tho there are a *lot* of branching paths in the game, so IDK how many I've missed), is when they skip the docking fee. One of the choices results in a very involved romp, but others very much don't, and Spark gets a choice in it all, so it's more on her, and the player.