Ballister Blackheart was once a fierce enforcer of the law until his best friend betrayed him and blew up his right arm, after which he decided that the law was wrong. He follows his own moral code now, which occasionally involves genetically engineered dragons. Partial to sardines and genetically altered anchovies.
Nimona is an impulsive young shapeshifter who aspires to supervillainy and has convinced Lord Ballister Blackheart to take her on as his squire. While quick-thinking and innovative with her powers, she is disturbingly destructive and rarely gives any thought to consequences. She's trouble.
The Director is the shadowy figure at the heart of the kingdom's inner workings, and the hand behind many of its darkest dealings. As far as anyone can tell her name is actually Director. No one knows much about her, and no one really likes her, but it's not her job to be liked. She has work to do and no one had better get in her way.
Enthusiastic, optimistic, and a little scatter-brained. She's traveled far and seen some things, nothing much fazes her anymore. Very excited about science. Not a witch. That's what she says, anyway. Magical scientist. (Probably not a witch).