Nimona

An excellent tale of petty heroes, heroic villains and the best darn sidekick one could ask for. The titular Nimona is a shapeshifter who wants to apprentice to the town's arch villain, a Megamind-esque mix of brains and failure.

Nimona's shapeshifting and utter lack of conscience bode well for his future prospects, but he reins her in with kindness just as much as she pulls him out of futility.

It's a slightly sad book, in that we must learn (as we always do) that you can't save everyone. But we can be comforted in that the best never fail to try.