Kongou failed as Episode 5's flagship because, although she's a skilled combatant, she has about as much tactical acumen as an overripe tomato. Proof? Play the game and see how often she aims for (and massively overkills) the enemy destroyers rather than shooting the really dangerous targets. (Granted, the same is true for virtually every other ship. But somehow it's more obvious when you hear BURNING LOVE.)
Rendering Kongou's nickname for Fubuki as "Bucky" makes more sense than making it "Buki" because Fubuki means "blizzard". Bucky? He became the Winter Soldier.
Why is it so hard to make the Abyssal Fleet stay down? Well, the IJN actually had the very same problem with Allied fleet during World War II. CV-5 USS Yorktown was reported to be sunk 2 times before she was torpedoed by a submarine shortly after Midway. IJN announced that they sunk CV-6 USS Enterprise three times, leading to a nickname "Grey Ghost" for her tenacity. Even in Pearl Harbor, battleships West Virginia, California, Nevada, Tennessee and Maryland sunk by initial attack, were returned to service after extensive repairs.
In the anime's opening theme "Ocean Colours", the first line in the stanza before the chorus goes "So foolish, Don't repeat the tragedy" It's spoiler about episode 11 and 12... And Kisaragi's fate.
In game, crossing the T boosts damage dealt to both the enemy and the player's fleet. In Real Life, when crossing the T, warships simply rotated their turrets to aim at the enemy to focus their firepower. But the Kanmusu, due to the manner in which their rigging is mounted on their bodies, would have to directly face the enemy while moving sideways, which is a rather awkward manner of doing battle.
Re-class is very powerful, but only shows up (in the browser version at least) in 5-5. Why? Because as a fusion of battleship and carrier-to a much greater extent than the player's aviation battleships, due to her plane capacity-she must consume about as much resources as Yamato and Akagi put together, making her prohibitively expensive for the Abyssal Fleet to deploy. Therefore, they only station her in a single map.
Kongou: The voices that echo across this boundless sea. Those girls' screams of horror, of lamentation, of resentment, and of their fear of death.
—"The Eventualities of Weapons That Learned to Love", by Ikezaki Misa. (Found on Danbooru, link not provided since Danbooru isn't safe for work.)
Furthermore, Nagato vaguely remembers Operation Crossroads. Just imagine the kind of freakout she'd have if she realized that she had been nuked back then.
As they are pretty much people, what do you think happens to these girls when you 'scrap' them? Can you imagine 'crafting' one of them? There is a lot of implied Body Horror going on, such that some fanworks, especially the nsfw ones, go into great detail about the darker element of fielding what are basically heavily armed girls. Indeed, it's popular in some doujinshi to depict the girls getting arms or legs torn/blown off when their ship-selves take serious damage.
Some fans suscribe to the theory that Ship Girls are basically summoned kami of the warships, and "scrapping" removes their warship powers and turns them into mundane humans. Some 4chan users immediately imagined a shoreline where many duplicate-summoned Nakas that had been scrapped were trying to float on the water as shipgirls but failing. One user immediately followed up with a short paragragh detailing a scrapped shipgirl trying her hardest to float on the water as a warship, failing, and starting to cry while chest-deep over the loss of her warship abilities. The shorelines of the areas around a very scrap-happy Admiral must be very depressing indeed.
A very popular fan theory (so much that it's started to creep into a few official publications) is that the members of Abyssal Fleet are sunken Fleet Girls that Came Back Wrong as a result of their resentment for the carelessness or incompetence that caused their demise. And since Fleet Girls can be replaced by making new ones, it would be mean that, unless the Fleet Girls manage to wipe out the Abyssal Fleet with no losses, or vice versa, both sides would be condemned to an endless cycle of battles.
The anime all but confirms this. Kisiragi is sunk in episode 3, and the One-Eyed Wo-Class appears in episode 6. "Yorktown" is Kisaragi. When she is slowly sinking, she repeats "Give it back" and we are treated to a shot of Kisaragi's hairpin surfacing from the waters.
A lot of long time players know that it's nigh impossible to NOT get Fubuki before getting Nagato, Mutsu, the 4 Kongou Sisters and Kaga, and yet the anime shows that this is the first time the other girls seen Fubuki in the base. Doubled with the fact that she received her Kai Ni upgrade in January 2015, which only then gives reason for some admirals to keep her, fan theorizes that the Fubuki we saw in the anime may not be the first one to be posted to the naval base, but the first one to be used actively. Suddenly having Gen Urobuchi as a guest writer may not be too far stretched anymore.
However seeing as the Admiral uses Mutsuki-class destroyers in combat operations makes it implausible.
Episode 11 of the anime has a horrifying implication. Through her dreams, Akagi remembers her final battle and sinking. How many times has the same war been going on, over and over?
Airfield Princess's lines in Episode 12 confirm this: "Sink... again and again."
It might be not that bad, she ,and by extension, Airfield Princess, might just remembered her memory when she was ship.
Remember that episode 6's joke, where there are Shout-Out to game's scrap sound? Yes, it's a joke, but the fact that our poor Destroyers get scared made me wonder that it's just a joke or did it imply that "Scrap" isn't just removing Ship girl's armament as supplement material said... And, after I found Ascended Meme in this main and character pages, it's possible that we're giving creators some creepy idea...
And... I might read too much SCP Foundation, but can we really sure that admirals, in and out- universe, aren't LIED. Giving that in Kantai world, ocean is blocked by Abyssal Fleet and surely caused serious problems over island nations like UK and Japan, I really sure that this is where Godzilla Threshold will be used even it meaned some morality will be abaddoned...
Every plane is manned by a fairy. A LOT of planes are lost in battles. Some fanworks point out that destroyers and submarines regularly go on missions to recover pilots from the water.
Let's add some more Fridge Horror, in the Origins Episode fancomic named The Beginning, the artist said and theorized that fairy that you can used for one will be DEAD, I mean disappeared, after being used. Even if you didn't lose your kanmusu, you will either lose the plane's fairies OR that type of fairies. Well, except if you have utterly good luck.
The newly introduced Aircraft proficiency system in the Summer 2015 Event update allows the fairies to gain experience and achieve better performance in the battle... however their ranks may be downgraded when they are shot down, or even become stripped of its ranks entirely if the plane slots are completely shot down. This comes with the Unfortunate Implications that the fairies does, in fact, live and die along with their aircraft.
The 4-koma Fubuki, Ganbarimasu! reveals that the fairies aren't killed along with their planes when they are shot down, though they still have to adapt to the new planes from scratch, resulting in a temporary loss of ranks until they got familiar with their new aircraft.
The revelation of that the final boss in Kancolle Kai was located at Pearl Harbor have the grim implications to the residents of Hawaii, as it was implied to be infested by the Abyssals over the time when they were overrunning the world.
Bear in mind that USS Missouri is currently located at the Pearl Harbor today, with her bow facing the Arizona Memorial. The Central Princess being the Abyssal counterpart to the USS Arizona has the implication that the malice caused by the Attack of Pearl Harbor was too strong for USS Missouri to contain.
Even worse, the Panama Canal is represented by an Abyssal Boss, implying that the entire continent of North America has fallen.