I imagined Cassandra in the context of a sequel story to the excellent animated movie "Batman - Soul of the Dragon", in which she would become Batgirl, and travel around the world to find her missing mother and Batman.

The way I see it in my head, Shiva kept her, raised her, started training her, until she had to go on that mission with Batman, Richard Dragon, and Bronze Tiger, and never came back. That way, Cass has an emotional bond with Shiva already, but still a lot of years they never spent together in her childhood, like in the comics.

For the Batgirl costume, I tried to go with something simple and homemade : a leotard, leather stitched together for the cowl and cape, kung-fu shoes and belt, and basic gloves.