What to Expect
A zany adventure mixing science and fantasy, demons and space aliens, dragons and laser beams. What starts off as a disgruntled, subversive, sorceress using-but-not-happy-about-it demon magic quickly evolves into an imminent alien invasion and interplanar travel between Earth, Demon realms, and outer space.
What I liked
Character are relatable, and the plot flows fast. Things constantly change, and new creatures, technology, magic, and information pop into the story. The protagonist is an "average" person, in that it's very easy to relate to her reactions and choices (she's also a weather sorceress, so there's that to keep things interesting).
What to be aware of
The demons aren't the evil biblical kind, but rather idealised beings living in a utopian society. The aliens aren't really all that alien (too similar to Earth bugs in all aspects), and almost everything - from cats to aliens - is practically telepathic.
The plot is chaotic, leaning towards adventure rather than a prolong build-up of a conflict. Problems are addressed as they come up, although there are plenty of twists to compensate. There's also a strong paranormal-romance sub-plot, one that would otherwise merit a six-pack on the cover.
This reminded Felix of True History, by Lucian of Samosata, a similarly zany adventure from his own time. He was surprised that the demons were so accommodating to humans - his experience with extra-dimensional beings is less savory - and the science and magic to him sounded exactly the same.
Recommended for anyone who enjoys chaotic plots and a mix of science-fantasy. I would recommend first reading the prequel short, Demon Spawn, as it will give you both the background and the feel for the story.