This is the first ever drawings (sketches) of Wendel and Jesibel. Just look at how different they look from this pic (especially Wendel).

The original story was Wendel had summoned a succubus "for science" and fitted a collar on her that negated her soul stealing or draining abilities. And she became the science club's sex toy…"for science".

It evolved into Jesibel being tricked by Wendel into granting him powers and she was punished by her superiors…into being his sex slave. _{I'm noticing a trend here}

Then the story changed into the two of them being forced to share Jesibel's body a la Birdy the Mighty as punishment for (Jesibel) being outsmarted by Wendel, and (Wendel) outsmarting a demon.

The current version of the story came as I was writing it and was looking for a conclusion.