Past Sins
I recently finished reading Past Sins; it was my bedtime companion for a few weeks, but all good things have to come to an end eventually.
And it really was good; an intriguing story based on an interesting idea, a very well-written tale that made it difficult to put the book down each night and that kept me coming back for more. Certainly worth being published as an actual book, too; although it was obvious at times that Pen Stroke's not an experienced professional author, the book was better than several traditionally-published fantasy novels I've read in my time.
So here's some thoughts on it. This explicitely is NOT a review; just a collection of various things that went through my head as I read the book (and that I happened to remember after finishing it).
What issues existed were mostly stylistic in nature; the story itself was quite excellent, although I felt that the second half, from Night Mare Moon's growing unhappiness with her reign of terror and darkness to her eventual redemption, was a little weaker than the first. She came around quickly - perhaps too quickly; I think this could've been given more time -, yet her actions didn't reflect her shift in attitude. Perhaps this was just due to her own confusion, all the conflicting desires, pressures and expectations clashing in her mind, both internal (Night Mare Moon's essence) and external (Spell Nexus's influence), but it could've been made clearer.
As an example, take the part where the CMC are locked up in Night Mare Moon's dungeon for trespassing into the castle. Night Mare Moon didn't want to do this to her old friends, and only had it done to appease Spell Nexus, who initially desired to see the fillies hang from the gallows; yet she did it, even though at other times, Night Mare Moon had no problem putting her hoof down and standing up to her highest-ranking advisor and leaving absolutely no doubt about who's the ruler and who's the servant.
Indeed, Spell Nexus himself was a character of somewhat unclear motivations: on one hand, he had a clear vision of who and what his queen should be, how she should act etc., but on the other hand he also was clearly devoted to her, to the point of unquestioning loyalty. The aforementioned scene, like several others, made him appear more independent than he really turned out to be; throughout the book, he regularly appeared as a realistic advisor who (while being allegiant to his queen) had his own goals and motivations, and for the longest time, I thought that he'd eventually try to force Night Mare Moon back to her old self, or perhaps openly rebel against her and try to seize power for himself (quite possibly while trying to retain her as a puppet on the throne), but he never did. In the end, he was simply completely loyal to her, and I found that difficult to reconcile with his earlier attempts to steer her into the direction he wanted, his bloodthirst, and so on.
There's an explanation for this, of course: since his mind was clouded and controlled by Night Mare Moon's essence, he had both unquestioning loyalty to her and a specific vision of her. But the revelation of why he acted the way he did came very late in the book, and until then, his being torn between these two fundamental aspects of his thinking was not explained as well as it could have been. There must've been a lot of internal tension on his part, but this wasn't made explicit, and as a result he remained a character of poorly-understood motivation.
I distinctly remember thinking about this about two thirds into the book: he was really quite bloodthirsty, and I wondered why. Indeed, how had he become the leader of the Children of the Night in the first place? Were they an ancient cult that he happened to belong to, or did he found them? How did he manage to reconcile this with being the headmaster of Celestia's school for gifted unicorns? The eventual explanation - that he was corrupted by Night Mare Moon's remains while studying them, that he cast binding spells on himself to contain the corruption and keep it from spreading, and that in doing so, despite being successful, he also concentrated her corruption in himself to the point where it took over and controlled every fiber of his being - made sense, but until then he appeared to be evil just for the sake of being evil.
Speaking of bloodthirst, BTW, I was surprised how little violence there was in the book given its subject matter. Except for the big fight against the Everfree monsters roaming free, there were just two instances of violence: a ponynapped Twilight receiving a light cut in the ritual at the very beginning (which understandably left her fearing for her life, but which neither did nor was ever intended to do more than draw a few drops of blood that were needed for said ritual), and Twilight almost being hanged by Spell Nexus. Almost - nothing actually happened, she neither died nor got hurt, and nopony else ever did, either. Even Celestia and Luna, when battling Night Mare Moon, sustained only the slightest of injuries before being overpowered and banished to their respective heavenly bodies. Not that I'm complaining, mind you; I'm no fan of violence, especially the self-serving, senseless kind; I just expected the story to be darker in this regard.
Pen Stroke's characterizations of the wide variety of ponies that made appearances were perfect, BTW. I've already mentioned Celestia and Luna and the CMC; obviously the Mane Six also made appearances, but so did the Great and Powerful TRIXIE!, Twist, Cheerilee, Diamond Tiara and Silver Spoon, Mayor Mare, Derpy (dubbed "Ditzy" for unfathomable reasons) and Dinky and more. Pretty much all of them were spot-on in their portrayal.
The only one who was a bit of an odd one out at times was Twilight, perhaps. I was a little surprised that she didn't trust her mentor to not send an obviously innocent little filly to the moon in the beginning, to the point of hiding that filly's very existence from her; I was also surprised by how little faith she had in Celestia later on, especially when after Night Mare Moon's sentence was executed, she immediately assumed the worst, although I suppose this is understandable given everything that had happened previously and the tight bond with Nyx she'd developed. As Celestia observed, motherly instincts are very strong indeed, and Twilight came to see Nyx as her daughter fairly quickly.
But of course, Twilight's behavior was crucial to the story's unfolding, and these are very minor points anyway. All in all, she was exceedingly well-portrayed, like all the rest.
Twilight also got over her ponynapping and being cut very quickly, BTW; she was able to go back to the Everfree, to the site of the ritual no less, within days, and apparently neither received nor needed any counselling. Granted, she's a strong mare, but I wondered how realistic that was: imagine that you've been abducted, tied up, had a black bag placed on your head, and threatened with grievous physical harm should you attempt anything (in her case, having her horn snapped off), and now imagine that you suddenly feel a knife cutting into you, leaving you screaming in fear of death. Do you think you'd be over that in a few days? I don't think I would.
What else? I mentioned before that I felt the first half of the book was stronger than the second; I think this was also because it was less clear in the first half what would happen. In the second half, deep down you really knew that Night Mare Moon's reign would end, that Celestia's and Luna's banishment would be undone, and so on: the remaining questions were how this would happen, and what would become of Nyx. In the first half, Equestria's future was much less clear: the book could've gone in any direction, including many dark ones, and I appreciated the sense of unease that brought: the same sense of unease that the characters must've felt, faced with such an uncertain future.
I rather liked the constellation beasts, BTW: ursa minors, scorpios and lupus minors (and a major, even), as well as other denizens of the Everfree, like hydras and cerberi. I was also quite amused that on several occasion, Pen Stroke explicitely stated that they'd never tasted the pony meat they so desired before: he was really trying to keep the book non-violent there, even in passing reference.
The diamond dogs were mentioned in passing, but mostly just existed as a convenient explanation of how Night Mare Moon's castle came to be - underground initially, no less. I kept on wondering if they'd make an appearance later on, but they never did.
The book was refreshingly free of typos and grammar issues; all the proofreading really paid off. I caught a few typos anyway - mostly missing whitespace, fusing words that shouldn't be fused -, but they were few and far between. The typesetting and layout were also great; in all appearance, this really was a professional-quality publication, an actual book rather than just a printed, bound hardcover copy of an electronic text.
It also contained a lovely fan art section and a new side story, First Hours: a retelling of how Twilight first met Nyx, from the latter's perspective, very much worth reading. Apparently there's a few more side stories, written before this one; I wish the book had included those as well.
All in all? I loved it. I'd also say "buy it", but obviously you can't anymore, unless they're gonna publish a second edition. :) But do read the story (and leave a token of appreciation in Pen Stroke's tip jar!) if you've got the time and if you're interested in ponies. It's worth it.