Rider
Rider smirked at his response as she considered how best to respond.
Hmm, well, that certainly adds some spice to things, she thought.
Really, there was no down-side for her to this bet. She was an extremely strong Heroic Spirit, so it seemed unlikely that she would be defeated. And, once she beat him, she would be able to do anything she liked to him with no guilt whatsoever attached. And, even in the unlikely event that she were to somehow lose, she would be his slave and he could do with her as he wished, which, whilst not exactly what she wanted, was still definitely pleasurable. And, whilst Rider wasn't a fan of fighting pointlessly, a fight with a purpose to it was something she could enjoy.
"OK, I agree to your terms. If you somehow manage to defeat me, then you may torture and violate me to your heart's content. If, on the other hand, I defeat you, then I can do to you as I wish. But, be warned, all I will guarantee if you lose is that I will not cause you any permanent harm. I will give you some pleasure, but you will suffer the most agonising tortures and the most abject humiliation at my hands", she said.
"Oh, one thing, how durable are you? I need to know how much torture I will be able to inflict on you when I win", she added, smirking slightly as she intentionally baited him a little further.
After all, if he was at least a little angry with her, he would be harsher in the unlikely event that he did defeat her.