I've seen Gideon pop up in a few different places, and honestly, I think labeling the series with one genre feels a bit off. It's marketed as fantasy, sure, and the setting is this wild, gothic space where necromancers rule and the sun is a lightbulb. That part's definitely fantasy. But the tone and the main character's voice throw it into a whole other category for me. Gideon herself is a sword-swinging disaster with a trash-talking, punk-rock attitude, and the book is soaked in her sarcastic, meme-adjacent internal monologue. The plot structure—locked-room mystery, ancient secrets, gory fights—has a strong horror-thriller backbone too, especially in the first book. So, while the skeleton is fantasy, the flesh and blood feel more like a genre-bending horror-comedy with a dash of science fantasy weirdness. The whole thing is a glorious, unclassifiable mess that somehow works.
If I had to pin it down for a bookstore shelf, 'Gothic Space Fantasy' or 'Science Fantasy Horror' might get you closest, but even that misses the queer romantic subplot that becomes central later. It's really its own thing. The author seems to delight in smashing expectations, so trying to fit it into a neat box kind of goes against the spirit of the books. You read it for the specific blend of tones—the bleak, cosmic dread mixed with juvenile humor and sudden, genuine emotional punches.