I love Depraved Wholesomeness in smut.
Recently read a doujin where the FL had the power to become stronger the more her people believed in her ability as Queen, with the closer someone was to her as their belief in her, the stronger the boost.
Eventually the ML comes in and through Supernatural Shenaniganery becomes her husband. She's not necessarily opposed because she likes him well enough, but someone that close could totally fuck up her strength if she messes up even a bit.
This is a Hentai Doujin though and we all know where this is going, and the two of them develop a fairly healthy sex life, where she is reduced to begging, walking on all fours for him, classic degradation. In keeping for the whole 'slippery slope of corruption' sort of thing that happens with these things, she's totally accepted that she going to get massively weaker because what kind of man could possibly belive in a Queen that regularly gets on all fours to beg for him? Her husband apparently, since shes stronger than ever.
None of that is explored so deeply in the actual material itself since its an FGO doujin for Zenobia, which acknowledges her powers near the end to a climax of declaring Gudao her forever husband, but I really like the underlying stroy even if it wasn't the authors intention.
