The main plot of the book, at its core, is actually really engaging. Unfortunately, not only is it executed poorly, it's also hidden behind heaps and mounds of tedious stuffing.
The book has a very odd mixture of being both fast-paced and exhaustively humdrum. I'll try to explain what I mean by this. After the first 50 pages (of the 550 page novel,) my first complaint was that events happened way too quickly; without any characterization background or any kind of setup to make events seem organic, the events that kept piling up just seemed confusing. And yet, by the time I reached page 200, I was nearly ready to put the book down for good, I was so bored. Despite a lot of "stuff" happening, it all ended up seeming devoid of any substance.
By page 220 I was REALLY ready to put it down, but I forced myself to try to get to page 250, which is good, because things FINALLY begin to happen around page 240 or so.
Which brings me to my next complaint - general writing style.
1) There are WAY too many characters in this book. By the ending scenes, where 80% of the characters are in one room at the same time, I felt like I needed a bloody flow chart just to keep track of who was saying what. The main character, (a soldier,) encounters and hangs around at LEAST a dozen different officers and comrades throughout most of the book.
1b) As a consequence, most of these characters don't get very much characterization... but even the most prominent of these guys doesn't get a heck of a lot. This led to a lot of small scenes and lines that left me thinking, at first, "Gee, that seemed REALLY out of character for that guy to do." Then I realized, "Well, I guess I don't really know what IS in character for someone who's only had a few paragraphs of dialog over the last 100 pages..."
1c) At least half of these million characters are surrogate father figures. TWO wise old captains, a few preachers, a kindly king, a magic mentor, an admiral, a vice admiral, ANOTHER king, an ancient elf prince... for the love of GOD.
2) Speaking of dialog, the author chooses a lot of really weird phrases. One character's "ass smile" is mentioned about 20 times. The main character's peer/rival constantly calls him a "puke." And I've heard of ending sentences with "eh?" before, (like a stereotypical Canadian,) but never with "what?" before. As in, "It's a nice day out, what?" Very off-putting.
3) As a result of having a metric shit ton of characters, MOST of the scenes in the book are scheduled meetings. I'm not even joking. Like, "Lieutenant, gather characters A thru X in my tent so that we may discuss vague unimportant things."
3b) In EVERY single one of these scenes, the main character (a young soldier with the fate of the world on his shoulders,) either says, thinks, or does something that is outspoken, borderline rude, or just plain stupid, and has to be gently admonished by one of his 17 older male father figures.
3c) A fair number of these meetings get interrupted in the middle of a conversation that was JUST getting important and interesting... and rather than finish the conversation at the soonest opportunity, the characters seem to just forget all about it or make really lame excuses for why we have to wait several chapters before talking about it again.
3d) An annoying number of these scenes are interrupted by "a nearby commotion." Oy. Vey.
4) Sudden revelations should be used sparingly and should have enough context to make an impact, as opposed to just leading to a "wait... what?" moment. This author is awful in that regard. "By the way, I used to be a mage. Is that relevant?" "Did I mention this big obvious tattoo I've had through the whole book? No? Oops." "Hey guys I'm a royal prince. No biggie."
5) The action scenes are rushed, vague, sparse, and therefore are usually confusing or unsatisfying. I could go on and on but I'll leave it at that.
In conclusion, if a competent author had received a one-page brief on this book's core plot, he could have done something wonderful with it. THIS author created about 75 compelling pages and 475 pages of tedium.