The Abyssal ships represent not the grudges of the shipgirls but their ambitionsThis would at least apply to the Abyssals which have clear ties to active shipgirls. In classic Japanese Spirit fashion the 'souls' of the defeated IJN ships were literally hell-bent on overcoming those that defeated them and ended up following Imperial Japan's method of taking what they deemed advantageous from the superior side. This would reconcile the idea of them being ex-IJN (and Third Reich) ships with that of them being Allied ships at the same time - they're Axis ships supernaturally 'modernized' with Allied equipment.
The game, as it were, takes place in a proxy afterlifeThis was brought on recently by the realization that the (as of this writing) Fall 2013 Event is based on the freaking Naval Battle of Guadalcanal, down to the bombardment of Henderson Field for the final phase of the event. Heck, the third phase (E-3) is even titled Ironbottom Sound, the area between Savo Island and Guadalcanal where many ships the kanmusus are based on met their end. This made me think that what we're really seeing is the spirits of the IJN ships (or maybe the resident kami that Japanese believe to reside in everything) are unknowingly reliving the encounters that got their "bodies" sunk in the real world. Given how many of these ships met violent ends (it was war after all), their spirits are fighting these battles again and again until they let go of whatever grudges they had upon sinking, so that they could move on to the next phase. Which leads to the next whacked out theory...
The Abyssal Fleet the kantai girls are battling aren't simply the "grudges of sunk ships" as implied by the 4koma...They're the grudges of the Allied ships sunk by the IJN during the war. This theory was brought about by the fact that Abyssal Fleet ships use the English system of measurement for their gun calibers (5 inch, 8 inch, etc.), in contrast to the metric system used by the kanmusus (12.7 cm, 41 cm, etc.). If these were kanmusus sunk by careless admirals, as the fandom thinks, then wouldn't they be using the same measuring system? The thing is (and this was after watching documentaries like Discovery channel's Battlefield series), only the calibers of US ships are ever described in this way. Add to the fact that the Fall 2013 seems to be a direct reference to the aforementioned Naval Battles of Guadalcanal (down to starting with night battles, something the IJN mainly did during that campaign), it's easy to put the two together... Which makes one wonder if the monstrous forms of the Abyssal Fleet are simply a type of glamour to make it easier to fight the Abyssal Fleet... instead of fellow shipgirls of the US navy just doing their own missions (like, oh, defending vital airfields), while the US-aligned shipgirls think they're fending off the monstrous forces of the Abyssal Fleet...
- Doesn't really work; the Abyssals have aviation battleships and tons of torpedo cruisers, neither of which were used by the Allies. They never even designed torpedo cruisers.
- While the Japanese kanmusu are indeed based on historical ships, we can't guarantee that every other nation is going to follow suit; perhaps Allied shipgirls were remodeled to be more like Axis ones after seeing how well the Japanese fleet was doing against the Abyssals. It's also possible that the Abyssals are able to reconfigure themselves to become different types of ship than the original, which would explain it.
- Plus the US did copy and adapt Japanese night battle doctrine. Maybe here they didn't stop there but adapted those ship classes too. After all, they did have the flip side of the aviation battleship, the gun-mounting carrier, for a short time with the Lexingtons.
- As a rebuttal, the Abyssals also have heavy cruisers armed with triple 8-inch main batteries along with torpedoes. The US was the ONLY nation that fielded triple 8-inchers, and the combination of triple 8-inchers plus torpedoes corresponds to exactly two classes of USN heavy cruisers, the Pensacola and Northampton classes.
Fusing the two above theories; every ship has two parts of their soul. The grudge that they had when they sank, and their original umblemished soul. The grudge will seek out the soul of their original enemy.Somewhere; separated by either oceans or dimensions, there is a fleet made of the souls of cute Allied Ships fighting the grudges of sunken Japanese ships.
- The separation occurred when aliens tried to animate fallen ships. The grudges were too strong.
- Nirvana can only occur for the ships if they seek out and find their counterpart grudge; and defeat/fuse with their Enemy Without.
- The Summer 2014/Aleutians-Midway Campaign Event just adds more fuel to this theory, as the lines of Midway Princess and the Carrier Princess imply that they're the nightmares or dark sides of Akagi and Kaga brought to life, respectively.
- This changes the WMG a bit. The Abyssal Fleet aren't Allied Grudges, they're the Ship Girls Grudges. Using Allied measurements for weaponry then is part of the Ironic Hell.
- Those two specifically may even represent Akagi and Kaga's sister ships Amagi and Tosa, who were never completed due to certain circumstances. Amagi was undergoing conversion to an aircraft carrier like Akagi when she was severely damaged in the Great Kanto Earthquake of 1923 and consequently scrapped. Kaga was tapped as the replacement while Tosa was never completed as part of the Washington Naval Treaty of 1922. She was used as a testbed for armor layouts and later scuttled. Think about it. Akagi and Kaga's stillborn sisters have come back from the dead eager to slaughter the shipgirls who got a chance at life.
- Adding credence to this theory is the Light Cruiser Dwelling Demon boss in the Winter 2015 event (Operation Hailstone). She looks like a fusion of light cruisers Naka and Agano, both of whom were sunk during Operation Hailstone.
The setting is the future of Strike Witches.The Neuroi were Time Travellers as well as space. When they descended on Earth, they stopped World War II from happening. Oh, many of the events were the same because of their engagement; but it was the Neuroi who took the dark karma. Hitler's Time-Travel Exemption Act, Godwin's Law of Time Travel. Averted. A planet united, humanity turned to White Magic and the purity of the souls of their children, and destroyed the Neuroi; and drove the shattered remnants of their flying ships into the sea.
- The Neuroi didn't understand what they had tapped into. Time Travel is not "clean." The erased timeline always reminds reality that it had existed, and it was in the dark places at the bottom of the ocean that the Neuroi embraced dark magic; the opposite of the Strike Witches; and took it to the next level. Where the Strike Witches donned aircraft and augmented it it with magic; (and unknowingly the persona of men fighting The War to End All Wars), the Neuroi reached into the other world and took their fallen ocean ships; and amplying their grudge, became them. And the Abyssal Fleet was born; alien science, dark magic, and the grudge of the fallen all fused.
- The magic of the Strike Witches was not enough against this. It wasn't a question of air superiority; or tactics. By definition; the Abyssal Fleet made their existence into a No-Sell magically. But once again; the aliens taking the darkness of humanity from the other world and embodying it left a weakness. If a Strike Witch was willing; she could give up her humanity (but not her shining soul) and become the embodiment of a Ship Girl; the ideal of a weapon in a war that was never fought in this timeline. The Neuroi became the grudge, the Ship Girls became the personification of courage, of duty, of sacrifice.
Kantai Collection and Arpeggio of Blue Steel takes place in the same universe.More accurately, Kantai Collection takes place after Arpeggio of Blue Steel. Sometimes during or after the war against the Fleet of Fog, humanity managed to either capture or re-create them, putting them under the control of humanity like Iona, as well as developing the technology far enough so that even destroyers and minor ships get to have their own Mental Models as well. Sometimes further after, the new Fleet of Fog, now called kanmusu or shipgirls to avoid the negative connotation of the old name (or the technology has advanced to the point they are different things), gained relatively equal rights with humanity and they are eventually assimilated into human society thanks to their new appearance. It is quite likely that somewhere in between, the nanomaterial used to build the "dummies" of the Fleet of Fog also advanced to the point it can be used to mimic human body perfectly while retaining the same destructive power. The Crossover event in Christmas 2013 suggests that the weapons of ship girls cannot penetrate the Klein Field of the enemy. However, it takes but modifications (presumably to be rather simple, seeing that the entire arsenal can be modified without consuming many resources, and the Abyssal Fleet also get to have them) to make them only slightly less powerful than the Fleet of Fog. Combined with the fact that ship girls are stated by canon to be somewhat human in size, that means that ship girl technology is actually more advanced than the Fleet of Fog despite the objective differences in firepower. This technology is also seen in the form of repair buckets, which can instantly repair Fog ships, as well as Damage Control equipment, which can prevent them from sinking; the Repair Goddess in particular can even restore a Fog ship to full health, fuel and ammo instantaneously, at no additional cost (read: without even using nanomaterials). The Fleet of Fog has no known equipment with anywhere close to similar functions. As for the Abyssal Fleet, they might be The Remnant of the original Fleet of Fog, or other projects that might or might not be the precursors or ship girls.
- Crossover events aren't proof for or against this theory. Take the short story crossover fight between Kirito and Silver Crow. It's implied in-series that the Accel World setting is the future of the Sword Art Online setting. The fight, however, was straight-up portal crossover, and wasn't canon in any way that would change either setting. No Time Travel worries.
- Alternatively, both Kancolle and Arpeggio happened on the same timeline but branched out differently; two different branches from the same trunk, so to speak.
Kantai Collection and Axis Powers Hetalia takes place in the same universe.Aside from the fact that close to everyone is a personification of some sort (whether ships or countries), it wouldn't be surprising if the Admiral the IJN ship girls answer to is Japan himself.
Kantai Collection takes place in an Alternate History where the "Good Guys" and "Bad Guys" of WW2 have been flipped.In this world, the OTL Axis powers-or at least Japan-are free and democratic and defending themselves against a fascist US and her allies. The Abyssal fleet is the results of American attempts to make their own kanmusu.
- Jossed with the reveal of Iowa as a character.
In line with the above, the Abyssals are the result of the fascist US's equivalent of Ghostapo.Maybe it was the other way around? The fascist American Ghostapo calls on the creatures of the deep, resulting in the Abyssals. In response, the Japanese turn to Shinto and create the kanmusu.
In the Kantai Collection world there is an enormous Eldritch Abomination under the sea.And it doesn't care what is going on at the surface, it doesn't even bother. Everything that happens is just a side effect of ships having come to close to it when they sank. That would practically turn the whole setting into one huge Cosmic Horror Story.
The Winter 2014 Event will be another crossover with Arpeggio.This winter season, Kancolle will get its anime while Arpeggio will be getting The Movie. Is there a better occasion to host another crossover event? Plus, Arpeggio's story has advanced to include and/or shed more light to a few more interesting new ships (Vampire, Yukikaze, Repulse, etc).
- Jossed. All the way up to Winter 2016, no second Arpeggio crossover has occurred.
Naka in the anime will be relieved from duty (i.e. 2-4-11'd).This will probably be revealed at the start of her focus episode which shows what happens when a girl leaves the Fleet. It'll be a heartwarming and heartbreaking story where we get to see just why she's so set on becoming an idol. We'll see the other girls' reactions as she's packing, and maybe a bit about what she does after she leaves the base. Everybody will be lonely without her. And then, for whatever reason, she'll be re-commissioned right at the end of the episode, because Naka-chan drop rate.
- Jossed, but given that a second season has been announced...
Gen Urobuchi has something to do with the anime.Given how Kisaragi sank in ep. 3, which became a huge whiplash in tone up to that point, the Urobutcher has gotta be involved in the anime somehow.
- Funnily enough, the day the episode aired, Gen officially followed the Kancolle Twitter account.
Mutsuki's yet to move onIf Kisaragi's death is meant to mirror a certain show, then chances are (provided they don't sweep it under the rug) they'll also take another infamous twist, especially since it mirrors the theory of Abyssal Fleets being corrupted Fleet Girls. Case in point: Mutsuki's unrequited feelings of love for Kisaragi is going to eat away at her until she becomes an Abyss Fleet Girl.
- Jossed, at least for first season.
- Completely jossed,Kisaragi came back in the Kantai Collection movie twice,first time as an proto-abyssal but still fights on the kanmusu side which later perished again to be purified into a kanmusu,second time as a fully recovered kanmusu.
Re-class represents the USS Samuel B. RobertsRe-class is noticeably younger looking compared to the other battleships-her physical age appears closer to a smaller ship like a destroyer or destroyer escort. In real life, The Samuel B. Roberts was known as "the destroyer escort that fought like a battleship" due to her performance in the Battle off Samar. Therefore, when she shows up as an Abyssal ship, she has the fighting capabilities of a battleship, while retaining the small body of a destroyer escort.
- Alternatively, considering her number of attacks, supply of planes, and power on-par with or even exceeding some bosses, Re-class may represent all of Taffy 3.
Operation FS in the anime might not happen.The actual Operation was a plan to cut off Allied supply lines from Fiji and Samoa that was first postponed after the Battle of the Coral Sea, then later cancelled due to massive losses in the Battle of Midway. If Kan Colle follows the history leading up to the Operation then things might be going down hill pretty quickly.
- To make matter more worse, the Doolittle Raid just happened as well as that the Admiral is insisting to cancel Operation MO, making History Repeats undeniable for the next episodes.
- Confirmed. The Naval District is attacked in episode 9, forcing the fleet to cancel their current operations and focus solely on Operation MI.
Fubuki and Yamato will lead a Big Damn Heroes moment in episode 12.Firstly because it would be Book Ends - Akagi saved Fubuki in episode one and now she gets to return the favour. Secondly because after the elaborate setup Yamato had in episode 11, it would break the tropes for her to do nothing with it.
The teased new character accompanying Yamato in episode 11 is Taihou.Mostly based on the cosmetic similarities the silhouette shares with the actual character.
Season 1 will have a Downer Ending...History Repeats, and Operation MI ends poorly with the loss of Akagi, Kaga, Hiryu and Soryu. This also gives the Abyssals the opportunity to strike at the Guadalcanal Naval District, forcing the battered survivors of MI (including Fubuki, who wears a new uniform with red and black trim in remembrance of Akagi) to rush out and provide support. Fubuki is assigned as an escort to a group of cruisers led by Aoba, with the aim of bombarding the captured Naval District to prevent the Abyssals from making use of it. On their way there, they are ambushed by an Abyssal fleet that was mistaken for a friendly force and Fubuki takes critical damage. The episode and season end when she sinks into the cold, dark sea...
- Jossed; the girls manage to achieve victory with the help of reinforcements.
...leading to a Peggy Sue plot for Season 2....only for her to return to consciousness standing next to the Naval District's radio tower, where she was watching Akagi at the very beginning. With the memories of how things went last time and the combat experience she's accrued, she'll try to Set Right What Once Went Wrong as best she can.
- Jossed; See above's jossing for details.
In the anime, the Admiral is really Nagato.A common theory on some Image Boards, as a joking response to how the Admiral is never seen on-screen and Nagato seems to be doing his job for him. The fact that Nagato just happens to have the Admiral's orders stowed away after the Admiral's abduction lends a bit of credence to this theory.
The real reason we never see an Allied Forces ship-girl is......that they are fighting on a completely different front, with their own, grossly overpowered opponents. If the United States wasn't deploying their own ship-girls, the girls we see wouldn't just be fighting the '... Princess', they'd be fighting against the Abyssal High Command, which has been tied up dealing with the military juggernaut that is America.
- It's also possible that in the KanColleverse, the Allies have fallen to the Abyssals, who use their resources to replenish their infinite supply of Mooks.
- This actually makes a lot of sense, and also goes a long way towards explaining certain parallels between the Abyssals and the Allies. With the Allies also fighting the Abyssals, there are going to be casualties. And as we know, Abyssals are born from the grudge of fallen kanmusu. However, if a kanmusu hold a grudge, it would most likely be against the Abyssals. As self-hatred isn't exactly conducive for a soldier, it's likely that when a kanmusu becomes an Abyssal, the grudge would transfer to whichever group they were second-most likely to have a grudge against. Now who would, say, American kanmusu have a grudge against? Here's a hint: who bombed Pearl Harbour? That's right. The Abyssals the Japanese kanmusu fight aren't the Allied fleet, they're the grudge of the Allied fleet. It's equally possible that the Allies can't help because they're caught up dealing with Abyssals born from the grudges of Axis kanmusu.
- The recent unveil of Iowa is pretty much a joss in and of itself to this idea.
- Not necessarily. It could be an XCOM 2-style situation where most of the world is being suppressed by the Abyssals, but after the main resistance in the form of the ex-Axis forces force a breakthrough by defeating Central Princess, they are able to make contact with the Allied Forces. They send Iowa over as the ex-Axis are clearly in a better position to make use of her than they are.
Harbor Princess holds back her power...The reason Harbor Princess was so weak in the original event she was in was because she was holding back her full strength. Not in the case of Harbor Water Demon, in which she unleashes most, if not all of her full power.
- Jossed by later update. Harbor/Seaport Princess and Water Demon are separate beings, with Princess having her own map 4-5.
- Except that Harbor Princess becomes more powerful when her health gauge reaches its final segment, thereby confirming that she holds back.
The Abyssal Princesses', Demons', and other bosses' motivesI kinda wonder... maybe their motive is simply to get back to their friends, at least for the ones that used to be shipgirls. Perhaps the common mooks are the ones that corrupt them, and their minds are warped in the process, making them attack their friends against their own will.
Error Musume is a ship girl in disguiseThat "Young Leaf" on her hat gives it away. She's JDS Wakaba, or as she was known during WWII, IJN Nashi, a Tachibana-class destroyer.
Abyssals were created/summoned by IJA remnants.A bit of a stretch, but considering how Akitsu Maru has pale skin just like them, and the whole Raven Hair, Ivory Skin deal that she shares with some Abyssals like Battleship Princess and Water Demon. Maybe in the KanColle-verse an IJA equivalent to Millennium from Hellsing escaped to parts unknown in the dying days of the empire and created or summoned the Abyssals to take vengeance on the world that beat them once.
- Pretty hard to say, as some of them are based on Allied ships. For example, CL Tsu-class is obviously the USS Atlanta because it posses the same weapon as it is.
- Not much of an objection. Resurrecting your enemy's dead to use as your own is a time-honoured tradition of necromancy, one that Japlenniumnote would probably enjoy rubbing in the faces of the gaijin.
The very first Abyssal was the USS Merrimac/CSS VirginiaIt fits in well with their theme: A ship is destroyed in harbor rather than fall into enemy hands. This backfires, as the charred remains are built upon and reconstructed into one of the first of a new breed of ships, which is forced into the service of evil.
Light Cruiser Water Demon will be Sendai's counterpartGiven that Light Cruiser Demon resembles Naka and Light Cruiser Princess is Jintsuu, this seems pretty obvious.
Purely on paper designs like A-150 Super Yamato could eventually appear.The introduction of Graf Zeppelin in Fall 2015 Event, who was never finished in reality, suggests that Kadokawa will go the napkinwaffe route once they run out of completed capital ships to add. Also, more never-finished designs like Kaga's sister Tosa might show up.
- The 51mm cannon (quest reward) is slated for that particular ship, so it might as well be a foreshadowing.
The Abyssals aren't the Allied fleet...There are more than a few things that hint towards the Abyssals being the Allied fleet, or American ships in particular. However, if one thinks about it, things aren't quite what they seem. Considering the nature of the Abyssals, it's likely that they're not just attacking Japan, but the entire world. As such, every nation would be fielding kanmusu against them, and thus experiencing casualties. If a kanmusu were to hold a grudge, it would most likely be against the Abyssals themselves; as self-hatred isn't exactly conducive for a soldier, though, it's likely that the process that turns a kanmusu into an Abyssal transfers the grudge to whichever group the kanmusu was second-most likely to have a grudge against. Now, who would, say, American kanmusu have a grudge against? Here's a hint: they bombed Pearl Harbour. That's right: The Abyssals that the Japanese kanmusu fight aren't the Allied fleet, but the grudges of the Allied fleet. It's likely that they aren't receiving any help from the Allies because they're caught up fighting the Abyssals born from the grudges of the Axis kanmusu. Of course, there are Abyssals that are implied to be the grudges of Japanese shipgirls. It's possible that the Abyssals decided to try a new tactic in an attempt to demoralise the kanmusu, by making them fight their own former allies instead of other regions' ships, and may continue to do so in the future. Time will tell if they continue to bring up the ghosts of old enemies, or switch entirely to this "fallen allies become new enemies" policy in the future.
- With the recent reveal of American equipment in a recent update, this is surely becoming the case. What we need to wait for though, is the ship that the equipment in question is for...
- With the reveal of the USS Iowa, this may well be confirmed.
The KanColle "Earth" really isn't our Earth.Yes, there are some spinoffs that explicitly say as such. But maybe all the renditions of KanColle aren't on our Earth either. Those wacky names like W Island, Vanilla Gulf and Curry Ocean? Maybe they're not just Doylist No Communities Were Harmed things, but really are a sign of their Earth not being the same one as in Real Life.
Let's start guessing who will be drawing USS Iowa, and who her voice actress will be.To get things out of the way, it will not be drawn by the Pacific: World War II U.S. Navy Shipgirls crew, as Morgane of the Mists has outright said that the crew is not involved in any way, shape or form. For her voice actress, all there is to go on is that it will be someone who has not previously voiced a ship girl before.
- End credits has Yoshinori Shizuma as the artist of Iowa, the same artist behind the Akizuki, Nagato and Yamato-class ships.
One mission that will be featured in the upcoming movie (or possibly through the second season) would be a variaion of the Solomon Islands campaign
- As added bonus: Yuudachi will cement her reference to Gundam 0083 by bellowing out the infamous line like this:
Yuudachi: SOROMONYO! YUUDACHI WA KAITEKTA-POI!
Abyssals are an offshoot of the Ceph.Beings of vaguely aquatic appearance, they wage on us a war ordinary humans can't win. Unlike in Crysis canon the Alpha Ceph activated more discreetly and took a different approach. Destroyers are the Stage One, resembling whales like the canon Stage Ones resembled squid. Cruisers are where you can see the shift into Stage Two, mutants with more humanoid features. The capital ships, Demons and Princesses are the pinnacle of the adaptation to human methods, complete with looking the most outwardly human. Clarketech covers a multitude of sins as far as their seemingly magical abilities are concerned. One shudders to think what will prompt the Cephabyssals to initiate Stage Three... And the ship girls? Well, they sure as Hell didn't come out of a government procurement programme. Perhaps the would-be founder of a certain Mega Corp. encountered things from the stars and repurposed it for human use, hoarding it until the time is right. Well, with the emergence of the Abyssals, that time is now.
Ryuujou has Inferiority Superiority ComplexListening through her lines, she sounds like she isn't as sure to herself of her as she lets herself shown, was it asking what Admiral thinks of her in her marriage line, dismissing how she can match up to Akagi and Kaga with an awkward laughter and seeks attention whenever she can. In a sense, she seems to fear being thought of being Just a Kid, being the youngest-looking Aircraft Carrier and wants to be seen being as good as the others.
Central Princess may actually represent...Due to her introduction into the browser version as a boss in the Summer 2016, we now have her equipment loadout, or specifically, what her main armament is.......a pair of triple SIXTEEN-inchers, with the exact same stats as the player-usable Mk7 triple sixteens. What does this mean? Central Princess may not actually represent Arizona, but rather MISSOURI. Adding on to the above, she may well and truly represent Pearl Harbour as a whole. Her extreme vulnerability to dive bombers is a reference to how the Arizona was sunk, while her having the Iowa-class' main armament can be explained by her assimilating the Missouri museum ship.
Re-class is SCP-1264Re-class's arsenal is consistent with the ships that make up the heart of SCP-1264. She has 16-inch guns (Nagato), can fire torpedoes (Lamson, Apagon), can carry and launch aircraft (Saratoga), and can attack and sink submarines (Lamson). SCP-1264-A are the fairies that operate her equipment.
Allied ship girls represent an inverted 442nd Regimental Combat Team.The 442nd Regimental Combat Team was a World War II unit of the United States Army comprised almost entirely of Japanese Americans who fought for the US against the Axis, admittedly not in the Pacific Theater against their ancestral homeland. With this as an analogy, you can reconcile the existence of Allied ship girls with the "Abyssals are Allies/Americans" theory: Abyssals do actually represent the Allies or Americans, but some of them chose instead to fight in defence of mankind and thus manifest as ship girls instead of Abyssals. For added symbolism, Iowa was a reward for smashing Abyssal-held Pearl Harbor in Hawaii, with that state being where the majority of the 442nd were from.
The very first Abyssal ship ever encountered by Japan was an Abyssal version of the USS Mississippi......a.k.a. the flagship of Commodore Perry during his voyage to Japan, and therefore the flagship of the Black Ships. Probably the antithesis of canon, considering that was way before WWII, but I think it'd be a nice parallel.
If KanColle gets a Darker and Edgier sequel, the ship girls will fight against the masterminds behind the Ship Girl-Abyssal cycle: the Leviathans.It's just a wishful thinking, but think about it: the Leviathans are based on Nazi Germany and they're Always Male. They might be even worse than the Abyssals in terms of malice and have the potential to become Omnicidal Maniacs.
- Appearance-wise, the Leviathans are Kaiju-style anthropomorphic marine lifeforms mixed with all types of weaponry (assault rifles, handguns, bladed weapons, etc.) and named after the genus of which species they're based on.
Trying to reconcile/make clear of theories of the Abyssal Fleet's originsIt's been discussed a lot that "grudges of sunk ships" are the more common theory (which the 4koma supports), so let's be clear: The Abyssals are the grudges of all kinds of warships in the WWII regardless of sides.'' Then, the bosses also seem to be closer to the "whole" ship/installations represented, ans their relative strength is one proof of it. My theory is that the mooks are simply rough amalgamations of multiple ships of the same/similar types, while the bosses are close to "pure" incarnation of what it represented in the past, and that is the probable reason some of them "turn back" into ship girls after they're defeated.
In the anime, "the Admiral" is an office, not a person.The Admiral who met with Fubuki at the start of the series was killed in the attack on the naval district, and the one who arrived in the final episode was a new, different Admiral. The fleet girls are only capable of perceiving someone wearing an admiral's uniform as the Admiral, and cannot distinguish between them as individuals.