Did not finish at 25%
This reads like Plato talking with Socrates, or other theological/philosophical ancient texts. Unfortunately there is so much jargon and dull lecturing explanations that I wanted to fall asleep and started to get glazed over while reading.
While there may be a good story to be gleaned here it was you much work to read and get anything out of the writing for me.

Maybe a philosophy major or someone with education or serious interest in the philosophical discussion of the afterlife, religion, souls, etc would be interested; but for me it was too much effort to muddle through any further.

An ambitious book with complex world building, I nearly gave up on Iron Soul because I felt like it was too much for one story. But, I stuck with it and really enjoyed the ending. Here's just a taste of this book: there's multiple worlds in which the dead spend their after lives that all have their own sets of immortal (sort of) warriors each with their own unique magic system, the struggles of the dead stuck on Earth, the plight of the dead who don't know that they're dead, the living who have no faith and no where to go after they die, the spaces between the worlds that are filled with monsters, a sophisticated system of hierarchy and trade among souls, a process of augmentation of powers among the dead, souls trapped in dolls, animal spirits and soul bonding...

That's all in addition to the basic story line- Aldus fights spectres and saves lost souls, he is called a Ferryman. While out on duty, he finds a powerful soul bound to Earth, whose name is Robert. Together, with a Jewish warrior named Benjamin, an ancient animal spirit, and an unlikely wandering soul who is bound in an unexpected container, Aldus and Robert will face one of the greatest threats that the living and immortal worlds have ever known- a mad man who will stop at nothing to allow spectres (monstrous spirits) to enter the world and prey on the living. Like I said, this is very ambitious and well-conceived novel but I felt that the book, like Robert in his earth bound chains, struggles under the huge weight of so many story elements.

This all sounds far more negative than I was intending this review to be. As I said, the ending packs quite a punch (in more ways than one) and if you can wind your way through this book, there are rewards to be found. I very much enjoyed the character development, the relationships between the characters, and Robert's awesome ride (which I will not detail here as it is one of the best parts of Iron Soul in my opinion). Recommended for readers who enjoy complex science fiction/fantasy and truly unique concepts.