This review may contain spoilers
The Pony POV Series Wedding Arc, by alexwarlorn is a tragic mis-step. Though it does avoid some of the larger problems of the source material it is based on, it sadly repeats some and enhances others, while adding its own mistakes to the mix thanks to contradicting not only established in-setting facts, but contradicting itself.
The basics of the plot are identical to source material: The upcoming wedding of Shining Armor and Princess Cadence is an excuse for the Changelings to launch an attack on Equestria. Unfortunately, it also carries the same attendant problem that the existence of Changelings causes in canon: One can no longer truly trust anything. And in this setting, that problem is not only enhanced, but made a key part of the story - it effectively confirms the world of ponies to truly be a crapsack world below the surface, in contradiction to prior claims made in the fic.
One error it at least avoids is that Chrysalis has a clear goal and is by no means a sympathetic character (not that she was one in canon, for that matter), but it sadly nullifies this via telling, rather than showing. We're simply told to believe she's managed to pull off a massive infiltration of Equestrian society,to such a degree she effectively controls the military, and has been at this for decades. How many, we are not told.
And this somehow escaped the notice of three goddesses and the military. It is implausible such a scheme could be pulled off without a failure at some point exposing the entire thing: Accidental detection of these infiltrators alone should have ruined it. And yet, somehow, by utterly defying all common sense and logic this is presented as evidence Chrysalis is intelligent.
Yet even that is blunted, for it emerges she relied on a cheat sheet, forewarned of canonical events and altering her plans to suit it - a cheat sheet based on a huge plothole that contradicts established events. It seems more that her adversaries were far too stupid or trusting in their own society than her intelligence scored her this win - and either way, the mere fact this can happen tears apart the idea Equestria's love and tolerance is a safe concept.
There is also the simple matter that, if such a plan was possible to pull off, then Chrysalis has elected to perform it in the most overly complex manner imaginable. If her control of the military was so great she could have simply overwhelmed the good guys. Instead, she uses overpowered spells and ludicrously contradictory mind control powers, whilst also managing to survive a direct attack from a sun goddess. In canon it was perhaps explained as that Celestia is not a bona-fide god, and may just be a powerful pony: but here it's utterly inexcusable, even with pithy efforts to handwave it away.
And speaking of gods, another issue here is that the entire root cause of the scheme is the meddling of an OC character, a goddess herself: Discord's sister, Pandora. Supposedly a goddess of creativity (though quite why this aspect was handed to a Draconequss, is never made clear... nor is it made clear why the entire pantheon is even necessary in-universe let alone to the story) all she has ever done is destroy. She was the root cause of a major threat in the Shining Armor arc, and was the very creator of Chrysalis.
In short, as with canon, the plot relies on the idiocy of the heroes yet again, and the informed attributes of overpowered villains verging on mary sues. It can also all be laid at the feet of an incompetent goddess who does far more harm than good - again. It also blindly ignores the consequences and implications of all it does, and where it notices them, pretends this is all fine and that nothing is wrong.
The actual writing itself seems both paradoxically rushed and yet slow paced. It seems that fifteen chapters is barely the halfway point and it has already wasted much of that time on scenes that add very little to the story, as well as taking plenty of time for petty take thats and digs at critics, other fics, and common complaints against canon - complaints the fic usually turns around and repeats.
The editing is lacklustre and seems to be virtually non-existent. The author and editors have missed scores of spelling and grammar errors in every single part to date. Dialogue is sometimes crushed in-between exposition and mashed into other dialogue, with long meandering sentences suddenly breaking into quotation marks, a problem not helped by inconsistent layout. There are also significant consistency issues relating to previous works in the series and even within the story itself. Numerous aspects that should at least gain some kind of passing mention are completely ignored.
The general actions of everyone on the side of good can be summed up as idiocy. Ponies blindly follow the stupidest of orders, from soldiers to common civilians, and the story barely even touches on the wider ramifications of these events. It blithely ignores much of what has gone before, even effectively ignoring the entire world outside Equestria and the nature of the Royal Guard in this setting.
The story also suffers greatly from an overly dark nature, to the point some readers may simply stop caring as the whole thing spirals down into horrific grimdark. We see ponies maimed and injured with barely any surprise by other characters, and the only ones who even bat an eyelid at the frankly ridiculous removal of all the Royal Guards are the few Guards left behind - themselves spared for ludicrious reasons.
There is also a real lack of scale or understanding expressed by the story, with easy logistics a key part of the whole plan. The author displays an inability to have a specific timeframe, ludicrous measurements of distance, ludicrous failures to account for the sheer numbers of ponies involved, and an inability to even keep the number of POV characters in check. Thanks to trying to cover almost thirty different main and side characters with a day in the limelight, it slows the progress of events to a bloated crawl. Entire chapters focus on characters who still seem to have no viable role, and any role they will have will likely be as nothing more than scenery while other minor characters save the day.
Pacing is also inconsistent, jumping around all over the place and unable to stay focused on any one thing for too long. Combined with the efforts to throw as many pointless twists and turns as possible at the reader, the incoherent editing, the inconsistencies with prior arcs, and the sheer volume of frankly unnecessary side characters being covered, assuming this is a halfway point may be overly generous. It may barely have scratched the surface.
In summary, this is a mess. A bloated and lumbering hulk of a story, with sloppy planning and atrocious editing, inconsistent messages and contradictory claims. It's a convoluted and confusing mess that derails so much of what had been worked towards elsewhere in the series, and adds nothing to the overall story but a massive dethroning moment of suck for the writer and the series as a whole.
This is, sadly, just another terrible Changeling fic. Avoid it.