While it never got much past the concept phase, I think it would be fun to play a circle of stars druid as a magical girl. I was thinking this ancient elven man who learned a bit of the druidic magics of his people, but was always more fascinated with the stars. One day he connected with a group of gnomes who invented a flying machine that could take them to the moon, and immediately signed up for the trip. When he got there, he discovered a moon goddess that had been trapped there. They hit it off famously, he offered to help free her, and she turned him into a knight of sorts, giving him the transformation ability. When he transforms, he turns into this young, bubbly, vivacious eleven woman with crazy armor and the standard anime oversized weapon that is based on which form he transformed into. She still has all the same memories, ideas and goals, but with a completely different personality. It would be pretty entertaining.