King Dainn, meet Molestia
Here he was, mighty king of the caribou, his warriors standing around him, still cheering, the defeated enemy bowing before him in submission. And yet, something wasn't right.
He was going to do her of course, here and now. But something didn't feel right.
After he defeated Celestia, it was as if suddenly her personality had changed completely.
When they cut her horn and wings, she had an expression on her face like she was enjoying this, like this somehow turned her on. Under normal circumstances, this would immediately have earned her the purple, but he decided to give her the red for now since she seemed to be otherwise perfectly in her right mind, still fully able to grasp what was going on and react to it.
Now she was bowing before him like she should, but something in her movements, the looks she gave him, felt to him like she was actively coming on to him, even like she was going to force herself onto him any second if he wasn't careful.
He had no idea where this idea even came from, he knew full well how stupid and paranoid it was, that not only was there no obvious evidence to this but even the thought that it could happen was entirely ridiculous.
Was this magic? He was certain that Discord's protection was still in place and working. Was this some kind of "deeper" magic? He certainly couldn't tell anybody about this, his warriors would at best laugh at him and at worst immediately dispose of him for his weakness and apparent insanity.
He had to do her, here and now, there was no way around it. Also, wasn't this what he had been looking forward to since they had landed in Equestria?
When they began, she did fully submit to him physically. Any outside viewer would have just seen a mighty caribou male fucking a red collar who was compliant and submissive like she was supposed to be. But to him, it was more like she was playing the active part while he was the one who submitted, or his body to be more precise, to something he couldn't control one bit.
He didn't even utter commands or speak a single word. It would have been of no use anyway. It was like she was always one step ahead of him mentally, always already knowing in advance what to do next, often before he himself even became aware of what he wanted. His body moved to hurt her, he beat her while they did it, but while this was not different from what he would have done anyway, he did not feel as if he controlled any of his actions.
It was as if he was watching himself from the outside while his movements were controlled by someone - or something - else. She spoke words of submission, called him Master like she should, switched from begging for mercy to begging for more, exactly like he had imagined it, but it all seemed to him like she was only mocking him, parodying his views of how it should be, twisting them to the point where he couldn't recognize them any more.
The worst thing for him was that she didn't show any sign of fear, as if she was fully aware what was happening to him and was enjoying every second of it. He had the impression that this was just routine to her, like she had done weirder and more unspeakable (or at least more imaginative) things every day before breakfast even before the Fall. She submitted to him, and yet while she did it, she outmatched him in any meaningful respect.
When they were done, he felt completely exhausted. He was pretty sure Discord's boon was still in place, but aside from that, he felt like all energy had been drained from him on all levels: physically, mentally, even magically. He felt weak, sick. As if he had aged a decade within a few minutes.
Celestia panted heavily below him, but when she spoke, every single word sounded like it was chosen carefully.
"My King and Master, isn't it great that you can do this to me for the rest of your life?"
The Mighty Stag King's heart froze in terror.