Baron Chungo makes some very sexy extreme Femdom. Unfortunately, he stopped producing a new art about 4 years ago. I will be posting almost all of his online content with the exception of a couple female-on-female pieces. Here are his 3 sites/blogs:
1) Woman is my only God
3) Baron Chungo
Coxbones does a wide range of Femdom scenes other than castration. Here is is DeviantArt profile.