Nimona is the story of a young shapeshifter girl (she's, I would say about 12, the max 13) that shows up at the door of Lord Blackheart to be his new apprentice. We get excellent back stories to both Nimona and Blackheart and despite him not wanting her at the beginning they develop a great friend shifting on father/daughter or older brother/sister relationship. Blackheart still can't ever forgive his old lover Sir Goldenloin for blowing off his arm in a jostle (I mean I wouldn't either). He lives with all this bitterness at having no choice but becoming a villain despite most of the time Blackheart wanting to do things the right way. Nimona is impulsive and thrives on real evil which makes a nice pair. 
 This is a sort of dystopian fantasy setting with TONS of science yet in a medieval society which I thought was unique and refreshing. Overall, I enjoyed it very much. I read it in one sitting despite being over 200 pages. I think despite this being a young adult, it works very well for adults and it's a good jumping off point to graphic novels because it's a stand-alone. 
 I loved that there was subtle LGBTQ themes, I loved that the main female character was very confident and sassy but above all I enjoyed the relationship between Nimona and Blackheart, it was wonderful.