Keltham describes that thing he did, that Yaisa liked. For which she later quoted him a price, under Fairness, that was more than an order of magnitude more than any sex that Keltham had to offer in dath ilan was worth to anyone from Civilization.
He felt powerful while doing that, he liked controlling Yaisa that way, and he knows that's - something Carissa wanted him to be able to feel.
So he'll be able to feel it with Carissa, once he... is actually capable of making her respond the way he wants. Which is sort of a key ingredient in that powerful feeling.