I think I speak for every sounder out there when I say that the ultimate goal for me would be to be dommed and sounded by Mistress Nikki Whiplash. You can see her sub is in discomfort, at the very edge of this being too much of a feeling, but she firmly continues while seeming oddly caring or compassionate at the same time. She clearly cares for her subs well-being, but really wants to push the envelope of what’s possible. Cherry on the cake, she pays a special, genuine attention to making the urethra gape as much as possible, to the point where you can tell her it's a specific visual kink of hers, something rarely found in women from my experience. It's even more obvious when you notice the progress of Slave Red's cock gape over the years.
She's a level above everyone else.