Okay I finished Penitent and I'm pretty divided on it. There are plenty of "genres" possible in a 40k book, and Penitent really feels like a YA novel (despite me never reading one). The writing feels a juvenile a lot of times with jokes, that while they often hit the mark, don't feel like something an adult/daemon would say, especially with the previously established characters that lived at least a couple of decades by now.
The heroine also feels a bit too awesome for being a fresh out of school inquisitor. I won't throw the mary sue term since she is fallible and is not perfect at everything (just mostly good, but that's the norm of 40k heroes) but she is the center of the attention and a few characters get attracted to her pretty much immediately, and she knows a lot of things it's unlikely to be a knowledge taught to inquisitors in training.
Despite it the book is written well with good pacing, and it's hard to let go before finishing it. I really like that it showed what regular people know in a hive city, like that they don't think Astartes are real, but mythological figures. Being focused on a single world has the benefit of really giving it lore and character.
Overall I'll recommend it, especially with the ending note of the book. Just hope the next book comes in less than half a decade, since I forgot pretty much everything that was in the first book.
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