There are quite some games in which females submit to stronger monsters and some get pregnant, although unfortunely the gameplay usually sucks ass. The opposite, which you're asking it isn't that common I believe. You have Violated Heroine, but not found on this website, because some characters are clearly underaged (which it isn't not my cup of tea at all), but I don't think there are too many with "strong females".
You may like
Ideology In Friction or other OneOne1's games, but besides that there aren't much. You can use
Updates page to select the tags on the right side and search what you found, maybe are with female protag and monsters, but not sure about being "strong".
