If I recall the request correctly, there is an element of mind control here.

Q: What collars do you plan on putting on the Demonic Twins Melody takes on as her first Dominatrix assignment? I still think she's biting off more than she can chew frankly. (Which might be beneficial to some hilarity later on.) But even one as "over?" confident as Melody will want some anti-strength or magic-hindering enchantment to keep the twins from overpowering her. She's clearly mostly human after all. And the twins are succubus's who've probably got internalized magic behind them. A dangerous proposition without countermeasures.

A: Given the twins' minor shape shifting ability and demonic sex drive, any sort of lust enhancement would be counter-productive in terms of controlling them. Melody will probably elect to use a particular mix of pain and dissociation known as a command collar. When the subject is given an order in a particular commanding tone, the collar activates. If the subject does not comply they will begin to feel uncomfortable. Anxiety and guilt rise and the master's command weighs down as the most important thing in the subject's mind, like a long neglected responsibility. If they continue to resist, a mild hypnotic dissociation begins to take hold. If they continue to resust, the subject may soon find that they have carried out their mistress's orders without realizing it.

Of course this is just a insurance measure. And it's a fine line between getting what you want out of a sub and violating trust. Part of being a mistress making your sub realize they want to obey, and to make them play your games rather than fight the referee.

Q: Curious, is the anti-pregnancy enchantment the only one on Alison? I'm sure the cuffs she used to wear where a form of restraint early on. But I'd imagine they'd want a way to reel her in if necessary. Then again, she is physically weak. So outside of leveraging her purpose or some slick trickery, she's not going to get out of a fortress full of demonic soldiers. (And frankly, she's just is not clever enough to pull off such deception. Stupid? no. But not brilliant either.)

A: Alison doesn't really need to be broken, she just needs a small amount of force applied - enough for her to use as an excuse to herself. Just a little push and she'll fall right where she needs to be, and that push is best applied the old fashioned way. Anything more would be at best a waste and at worst might upset her natural proclivities.

One possibility is physical compliance where the subject's body obeys but they retain control of their mind and are free to voice their objections.

You could also add in possession or "switchboard" type effects where sensations, motivations, and actions are piped around from various sources. Something like the sensation mirroring in Wetware, for example. Or the lust amplification in the presence of a particular demon, as seen in Dark Altar. A subject could dissociate while a spirit is summoned into her, either from within the collar or an external source. Varying degrees of "co-piloting" could occur.

Iskath is a city to the north. Further away from the epicenter of the plane crossover anomaly that allows demons to appear but still effected by it. Occasionally a demon will materialize on their own, not bound by any ritual or contract, and cause trouble. Mistress has a knack for resolving these situations, taming the offending parties and occasionally leveraging her natural talents to smooth over political hurdles.

Melody has recently reasserted that she's supposed to be Mistress's apprentice, not just her hand maiden ( see outfit https://satinminions.com/bonus.php?sha=b6b7c2e419 ) and she has talked her way into coming along. Mistress will be on the lookout for any new projects that Melody can take on by herself.

Alison is staying behind because in any kind of intense scenario she'd just be a useless horny liability. Sure, she could be used as a payoff or distraction but that seems a bit cruel after she's softened so much. Plus there's the real danger that if she doesn't get on Torrin's dick soon she might actually explode.