I think this one has awakened something in me.

For context, Arle here has been captured to be sold as a slave on a market catered to evil wizards. As part of her preparation, her tongue is forced out and branded with a control rune, rendering her unable to disobey whoever the rune's attuned to. She screams in pain, the slaver tells her to be quiet, she instantly stops screaming and can no longer make a sound.
That's all well and good, but what gets me is that her tongue is left like that, pinned down to put her control brand on display to a clientele likely to know what it does.
And that's so fucking hot. Magical brands and tattoos advertised as perks of your purchase, extra features added on to the slave, arranged in such a way to present them as such. You could do it with accessories or non-visible spells too!

Imagine a slave standing in the market, completely naked, miserable or defiant but strangely not restrained at all. Her hands humiliatingly form a heart around some pubic tattoo. When asked what her deal is, she's dutifully explains, compelled by the spells to answer such questions no matter how little she wants to. Maybe tell her potential buyer that if he stands in this spot or says these words, that control will be temporarily extended to him as well as sort of a free sample.

Anyone else feeling this? Help me out here.