Nightmare Moon - T-shirt design sketch

Hello. I am working on design for t-shirts, referring to show: My Little Pony. ( for Welovefine.com - [link] )

Here is a sketch of design with Nightmare Moon. Not sure if character's pose is too simple. The character isn't detailed now, but her "hair" I would like show in this abstract style.

Inspired from Guild Wars 2 style.

What do you think?