Have you, at Riot games, ever thought of taking some characters, and making a skin that'd basically be the opposite gender they originally are? And if so; why haven't you tried the idea out on the community? See how the reception of an idea pans out with a poll or something. I understand you'd need a voice actor for each one, and to slightly edit the models, but you wouldnt need to modify the spells hardly any in the process.
Just a little food for thought. I'll take my leave now, and its just as a bit of a joke, so dont take this post too seriously, lol.