I like the idea that demons have an essential nature which can vary in intensity. As a result of this thought, I made a visual of how I see Buttercup's proper Demon form, as opposed to her normal Imp form (shown in the second picture). This is how I figure she looks when she has her character arc and can manage herself, not that she can't go back and forth once that happens.
Now that I've got Sporty Succ done, I should do Pop Succ and Gamer Succ as well. :P