I think I won't do a general Skill overview; it's at least on long hold, if not just axed entirely. So, more comprehensive faction overviews it is. Starting with Iron Blood, both because I'm already very familiar with their ships and because they have the smallest number of ships. I'm not sure if I'll do the smaller factions; I'm leaning toward not, but it'll probably depend on how I feel after doing the big four.
Iron Blood - Of Sharks and Dragons
Iron Blood is a very bulky faction. While not necessarily having the best values in each ship class (especially with Research Creep), they tend toward higher HP, and are comparatively slower and have lower Evasion.
Iron Blood destroyers are very invested in the gunboat line, with even their low-Firepower ships having pretty good Efficiency and usually the Piercing Shells skill to increase damage dealt with AP guns. Moreover, Z1 provides a massive 40% buff to the Firepower and Evasion of all Z-class destroyers, which also helps with their bad-by-DD-standards Evasion. They have fairly good torpedoes, with pretty high stats and okay-to-great Efficiency. Standout ships are, of course, Z1 and Z23; the former has an amazing boost to Iron Blood destroyers and is the best IB torpedo boat, while the latter is a powerful gunboat. Z46, the only inherently SR destroyer, is a bit more general-purpose, with modest FP (and high Efficiency) and high Torpedo (and low Efficiency), with a solid AA stat and Efficiency.
Also of note is the fact that the 1936A class - Z23 and her sisters - are capable of using light cruiser guns. As was mentioned before, it is almost always a bad idea to actually equip them with one, and even in cases where it
might not be a bad idea, it's likely that a destroyer gun wouldn't be of much less use, if any. (For anyone wondering, I'm thinking of cases where you might want to keep your ships farther back than normal for some reason, but CL guns only have a max range of 70 units, and there
is a destroyer gun with that range anyway.)
Iron Blood light cruisers are all torpedo cruisers, with the addition that Mainz has MGM +1 as well as (very poor) torpedoes. Mainz is also one of the best light cruisers in the game, with extremely high HP, Medium Armor, and great Skills; being a PR 3 ship, she is also pretty accessible, especially compared to Event-locked ships or Plymouth. Leipzig has very powerful Torpedoes and provides a general buff to the offensive stats of all cruisers, as well as increasing the Speed of the Vanguard and reducing ramming damage taken; her sister Nürnberg buffs all Iron Blood ships' AA stats and - probably more importantly - boosts the experience gain of submarines. The K-class sisters are (by now) fairly below average as far as light cruisers go; Köln has a unique ASW gear, but it's not particularly powerful and in the situations where it would be useful, you're probably better off using a different ship.
Emden and Elbing are unique in that they have no default AA equipment; Elbing can be equipped with an AA gun to help contribute to the fleet AA bubble, but Emden can not. Emden is also one of the few places where a light cruiser gun can be preferred to a destroyer gun: her
second weapon slot can hold either, but with a CL gun, her gun Efficiencies are increased and she gains a strong barrage with a Slowing effect, while a DD gun creates a shield that retaliates with a vampiric barrage if broken.
Iron Blood heavy cruisers are also all torpedo cruisers, with another pair of caveats: Roon (and her Idol version) is, like Mainz, MGM +1 with torpedoes, and Yorck (like Emden) has two gun slots but no AA slot. Roon is very accessible, and while her bulk is of limited value, she is still very powerful offensively, particularly against Sirens; her Reload buff, when using the Triple 203mm (SK C/34 Prototype), decreases her reload time by less than a second when it's fully stacked, from 6.25 to 5.55 seconds. Prinz Eugen,
once you have her Augment Module, becomes fairly useful thanks to being able to Armor Break any target, but with only a single Shield Skill and poor offensive capabilities, she's not good for much except soaking damage. The Deutschlands, on the other hand, have fairly low HP by IB standards, but their high Firepower, decent Efficiency, ability to equip a bombardment gun, and Skill that shreds DDs and CLs, make them very formidable.
The P-class are Deutschlands with even better stats. Similar Firepower, HP on par with Roon, even more Efficiency, same bombardment gun option, and they get a special ghost secondary. They are missing the anti-DD/-CL Skill, but they are much better general-use ships. Blücher, the third Admiral Hipper, is quite different from her sisters, with low HP but lots of Firepower and gun Efficiency, and Skills that increase ... basically everything. She buffs her FP, Crit Rate, Speed, Evasion Rate, has a timed Barrage, absorbs damage from the rest of the Vanguard, gains a special ghost secondary, has Shields, and - when at less than 50% HP - reduces her damage taken and increases her damage dealt.
Building an Iron Blood Vanguard
It depends on what you want the fleet to do, obviously. An all-destroyer vanguard is possible, but it's going to have some survivability issues even with Z1, and why wouldn't you use Z1? Just heavy cruisers might run into some issues with AA and submarines, although the former can be mitigated and the latter are usually not a significant threat.
If you're building an IB destroyer fleet, Z1 is
almost mandatory: that Firepower and Evasion buff is just too good to pass up unless you're doing something where you're already more than strong enough (like doing ASW in low-tier worlds or something). Additionally, her retrofit Skill can decrease the damage the Vanguard takes from aircraft, which is particularly useful if you're just using destroyers. Similarly, while Z23 isn't required, her sheer firepower advantage over other destroyers and her larger health pool (particularly if you have her Augment Module, which gives her 8% Damage Reduction and an additional 10% Main Gun Efficiency) make her extremely powerful. The third destroyer, then, is something of a wild card. Z46 is traditionally the third destroyer, as she has high gun Efficiency and HP. Z24 and Z28 are also good choices: Z24 has a damage buff against enemy DDs and CLs, and if another Z-Class ship falls to less than 30% HP, that ship gets 30% Damage Reduction and Z24 buffs her own Firepower, Torpedo, and Reload; Z28, on the other hand, passively buffs Firepower, Accuracy, and AA for all Z-class ships, and she also buffs her own FP, TRP, and ASW if she sorties with another Z-class destroyer.
An Iron Blood cruiser fleet is strongly recommended to have Leipzig or Emden; I'm not sure if both in the same fleet is going to be as useful as having another ship. Emden is going to be more useful if your Main Fleet consists of IB battleships or battlecruisers, however, while Leipzig only buffs cruisers. Mainz and Roon are very powerful, particularly in combination with either of the light cruisers. Ägir, of course, is a top star - although like Emden, she is more useful to a Main Fleet that has big guns rather than one with carriers.
Personally, I'm fond of Ägir/Emden/Mainz, especially in a Bismarck fleet: Bismarck increases the Crit Rate for IB main guns, and Mainz buffs her own Crit Damage; Emden buffs all IB ships' Firepower, and Ägir causes Armor Break (and increases her own Crit Rate as well). Both Roon and her Idol form can be sortied in the same fleet, and then buffed by Leipzig, or serve as tanks to support Blücher. The P-class can be sortied together (again, likely with Emden or Leipzig buffing), or separated to provide an offensive punch or tank for a lighter fleet.
The core premises don't even require the Event-locked ships: Z23 is a starter, and drops in the campaign; Z1 drops in several campaign maps as well; Leipzig is a reward for max-limit-breaking the K-class sisters, who all drop in the campaign; Roon and Mainz are PR Research ships and can be upgraded with coins, while Ägir is a DR Research ship who has to be upgraded the hard way; Idol Roon is available in the Core Exchange; Z28 is in the Merit Shop, and Z46 is one of the DD selections from the Medal Shop. The Deutschlands can't quite replace the P-class ships, and Emden isn't replaceable in the Iron Blood lineup (if at all), but it's still possible to create very effective Vanguards without using Event-locked ships.
As far as aircraft carriers go, Iron Blood is not exactly spoiled for choice. They have
two light carriers, and four fleet carriers. Fortunately, three of the fleet carriers are good.
Elbe and Weser have the problem that they're Light Aircraft Carriers with CVL loadouts. They have low Aviation and only six planes, three of which are Fighters, so they don't have much ability to deal damage to enemy ships, although they do both have potential special airstrikes that can go off. They also both have Shield skills, although Elbe's at least is tied to a damage buff for herself. Elbe is also noteworthy for having an extremely high Fighter Efficiency of 145%, which can be translated to AA ability or anti-surface damage with either the F6F HVAR or the Bf 109G. Iron Blood Fighters (109G aside, which has almost no AA capability) are incredible AA platforms, and the Me-155A is incredibly quick to reload, but neither the 155A nor the FW 190 A-5 have any anti-surface capability. Zeppy is a full Aircraft Carrier who can trade her third slot (two Dive Bombers) for a light cruiser gun; either way, its Efficiency isn't very good. She has a Firepower-based timed barrage that changes properties if she is holding a gun, and being able to shoot at enemies who get past the vanguard is an advantage that most carriers lack. Considering her comparatively low Aviation stat, it's probably more beneficial to have her carry around the gun.
Graf Zeppelin grants Damage Reduction to all Iron Blood ships and, if she has at least one Iron Blood plane, boosts
all her Efficiencies by
30%. That brings her up to 150/160/160 Efficiencies for Fighter/Dive Bomber/Dive-or-Torpedo Bomber, and makes her an incredibly dangerous striker. Due to the aforementioned nature of IB Fighters and the relatively poor performance of IB Dive Bombers, it's probably best to use the Ju-87 D4 Torpedo Bomber to activate the buff, particularly as IB torpedoes converge, which makes their point damage generally superior to parallel torpedo bombers. Peter Strasser is only slightly off from her sister in terms of stats, but has 10% more Efficiency for her Torpedo Bombers, has a special Airstrike, Slows all enemies with a chance to Stop them temporarily, and can reduce the reload time of IB carriers' first three airstrikes. The Slow isn't particularly powerful, and the Stop is incredibly unreliable, so her biggest advantage lies in her extra airstrike, followed by not needing IB planes to buff herself. August von Parseval has a weird setup; like the Zeppelin sisters, she has a 2/3/3/ plane loadout, but her Efficiencies are 140/110/140; while this is likely to be an attempt at balancing her so she doesn't obliterate lighter ships - she has a 10% buff to her Fighter Efficiency if she uses an IB plane, she has a special airstrike that increases the damage Light Armor and Medium Armor enemies take from airstrikes, she has a 20% damage buff against light and heavy cruisers, she has a guaranteed Stop,
and the Bf 109G is
very good at dealing with Medium Armor targets - it probably wouldn't have changed much if she had a 3/2/3 loadout instead.
Iron Blood battlecruisers are a little on the gimmicky side. Scharnhorst and Gneisenau are fairly weak ships, with poor base FP and only a single 150% Secondary, but they have a Torpedo stat, and a Skill that fires three Torpedoes; they are also the only IB battlecruisers that are Medium Armor; every other IB BC has Heavy Armor. Odin has comparatively low HP, less than 7300, but she also has 20% Damage Reduction. She also has Torpedo Secondaries, and high enough Stat Efficiency to do more damage with them than some Heavy Cruisers (probably
most, but I'm not willing to do the math on it right now); she also has two sets of Ghost secondaries, and one of her Skills moves her forward of the Flagship position, so she can fire those secondaries significantly farther than other Main Fleet ships. She
also has a timed barrage and submarine detection; the latter in particular also reduces the damage the Vanguard takes from torpedoes, and can (probably still) be used outside of an IB fleet to make Helena almost immune to torpedoes. (She's also, I believe, the Iron Blood BC/BB with the best AA stats at 345 and 110% Efficiency; she's actually pretty high up as far as BC/BB AA goes.) Odin is a solid ship; her Firepower is low (base of 369) and she doesn't have a secondary gun slot to boost it, but her secondaries will almost always have something to shoot at and she's actually quite hard to kill.
Prinz Rupprecht, on the other hand, has high HP with over 8600, and her own extra-long-range special secondaries on top of her actual Secondary Gun Mount. Those special secondaries trigger torpedo barrages every five times they fire, and buff her FP and TRP the eighth time they fire. She has positional Damage Reduction: if Prinz Rupprecht is the flagship, she gets 15% Damage Reduction; if she's not, then whoever is in the spot above the Flagship gets 8% Damage Reduction. While her base FP is fairly low (379), when the buff kicks in she actually becomes fairly competitive, although she still can't match BBs that have their own FP buff.
Brünhilde is, like Scharnhorst and Gneisenau, quite conventional: she has her torpedoes that are fired as part of her Skill, and a special attack that noticeably slows the target. She can increase the Accuracy of all BB/BC/BBVs in the Main Fleet, and she has a particular advantage against Light Armor enemies, dealing extra damage against them if she has IB gear equipped.
Seydlitz and Lützow have no inherent AA guns, and while they can equip them - Lützow even has enough Efficiency to make them fairly worthwhile - it's probably a better decision to maximize their Firepower by giving them another DD gun. Lützow has a buff to her Main Gun damage, a stacking firepower buff, and a damage buff against BBs and BCs, and a Debuff applied to enemies hit when she uses an AP or SAP Main Gun. AA gun and Torpedo barrage aside, Lützow, like Brünhilde, is fairly ungimmicky. Seydlitz, on the other hand, starts with a Reload buff for her first Main Gun Salvo that is dependent on how much HP she has left, ranging from a 20% to an
80% reduction. She also absorbs and reduces a significant amount of damage that would hit your other IB Main Fleet ships, which is counterproductive to the rest of her kit. She also has a zombie Skill, and a Damage Slider: when she has more HP, she deals more damage, and when she has less HP, she
takes less damage, up to 20% each way. She also has a buff to a select few ships: if she is
not the flagship, and a ship that has a 'Marvels of History' Skill
is the flagship, then that ship gains the same First Shot Reload Buff effect that Seydlitz has. Currently, the only ships able to make use of this are Lützow and the battleship Thüringen.
Iron Blood's pure battleships are defined mostly by very high HP (... and also, apparently, by being lousy shots), although Friedrich der Große for a long time had the highest Firepower in the game as well as the most HP; she has since been dethroned. She is still an extremely powerful battleship, and her only real competitors are Event-locked, making her an almost-accessible option for brute-forcing content. She has a straight 20% buff to Firepower and 20% Damage Reduction when maxed, a defensive barrage and an on-fire barrage, and a swapping Skill: alternating salvos either increase her Reload and damage dealt or her Crit Rate and Crit Damage. If she's somehow beaten down to under 30% HP, she also gets a buff to her Secondary Guns, increasing their Shell Velocity and Efficiency.
Ulrich von Hutten is currently the only gacha UR in the Iron Blood roster. Her stats are similar to FdG's, and while she is actually better in a few, Luck is the only one likely to make an actual difference in her favor (50 vs FdG's 25
after Fate Simulation). She has an on-fire barrage that slows the enemy a little for a few seconds; I've found it seems to mostly serve to keep the enemy from dodging her follow-up shots in the salvo rather than being of much use assisting other ships in the fleet. She also has a defensive barrage. She's probably most well-known for her ridiculous rate of fire: when not the Flagship, she has a permanent 50% cooldown reduction for her main gun, which generally allows her to be firing within ten seconds of the last salvo. She does take a hefty reduction in damage dealt, but between the facts that it's a
45% reduction and that it's only her Main Gun damage that are affected, she actually comes out ahead in DPS. Unless she has an Out-of-Ammo debuff, anyway, in which case you'll generally want her in the Flagship spot with her normal Reload and only the OoA damage debuff. She also provides benefits to friendly fleets for the first five battles they take part in: Iron Blood ships get a slight amount of Damage Reduction and a slight increase to their Critical Damage, and the fleet gets six defensive barrages per battle.
Bismarck is the Flagship of Iron Blood, increasing the Crit Rate of Main Guns, Torpedoes, and Aircraft used by Iron Blood ships, as well as IB ships' Reload. While not as continuously useful as raw stat buffs to Firepower or Aviation, it's still very useful, particularly for Research ships that have low (or no) Luck. That Skill also gives Tirpitz a
40% damage buff when she's sortied with Bismarck. When she's sortied as the flagship of a fleet, Bismarck also gains an on-fire barrage and increases the damage of Iron Blood carriers. Finally, the first volley of every salvo she fires is guaranteed to Crit, and if she equips light cruiser guns, their range is increased to 90 (from a maximum of 70), but their damage is reduced by 35%. Most of her Skills I have no problem with, but the last bit that affects her secondaries is a bit odd to me, since she already only has two secondary mounts
and they only have 180% Efficiency. It makes her secondaries useful for poking at ships that are proving difficult for your Vanguard to disable, but it actually makes her worse at anything that actually gets close ... and since they're her
secondaries, I'm pretty sure they don't even get the Crit Rate buff.
Tirpitz has a bit less HP than her sister, but
she actually has 200% Efficiency on her secondaries - and she has Skill-based Torpedoes as well. Her other Skill provides her with a 30% damage buff when sortied with no other battleships or battlecruisers. Then she got an Augment Module that changed her Skill to, "When there are
no non-Iron Blood BBs or BCs in your Main Fleet," and suddenly sortieing her with Bismarck gives her a
+70% damage buff. Even with a fairly conservative 428 base Firepower and 130% Main Gun Efficiency, she starts doing quite a lot of damage when she fires (although to be clear, the damage buff she gets are
general damage buffs, not just to her Main Gun). Unfortunately, that's ... really all there is to her.
Finally, there's Thüringen. Like the other High Seas Fleet ships - Emden, Elbing, Yorck, Seydlitz, and Lützow - Thüringen has no default AA gun. She can be equipped with one, but as with Seydlitz, she just doesn't have the stat or Efficiency to make it worthwhile, and is almost certainly better off with a spare DD gun boosting her FP. She has two unreliable Skills: a chance for her Secondary Gun (CL/DD, not the one that's AA/DD) to fire again after it shoots, with a ten second cooldown, and a chance to fire a barrage when her Main Guns finish reloading; enemies hit by the AP shells of that barrage have reduced Evasion and take more damage from Iron Blood ships for ten seconds.
Building an Iron Blood Main Fleet - and then putting it all together
The first question is how many aircraft carriers you're going to use. Three carriers? Use all three fleet carriers. Two carriers? Preferably use Zeppelin and August with Bismarck in the middle buffing them; Peter isn't bad, but her Slow/Stop is less effective than August's. If you're only using a single carrier, I'm not sure I would; Graf Zeppelin gives some Damage Reduction and can be used with, say, Odin or Prinz Rupprecht to help protect someone squishy, but I'm not sure anyone in the IB roster qualifies, not even Thüringen and her measly 6400 HP (why would you be running her in a fleet not dedicated to trying to make use of her ability?); if you're not using GZ for damage reduction and raw Efficiency, then you might use AvP with Odin/Prinz Rupprecht/FdG as part of an anti-Siren Research-only fleet. You're still probably best off with either 3 or 2+Bismarck, though.
Friedrich der Große and Ulrich von Hutten can (and should) be used just about everywhere; they have raw power that even buffed Tirpitz can't really match, and UvH benefits friendly fleets as well. Bismarck would be a useful third ship here, as she provides a noticeable buff to Crit Rate that both ships would appreciate - UvH fires a lot and has boosted Crit Damage, and when her Skill is buffing her Crit Rate (and she's packing the Super-Heavy Shell), FdG would be looking at a
+48% chance to Crit. Brünhilde would fit well with them, less for her Slow and more for her Accuracy buff: it is fairly minor, and various gears do improve it better than her Skill does, but it's still more accuracy, and particularly with FdG you want as many of your shots to hit as possible. Odin or Prinz Rupprecht, with their increased secondary armaments, can also benefit FdG/UvH by making it more likely for their defensive barrages to defeat anything that actually does get close.
Prinz Rupprecht makes for quite a tanky flagship, and the central position is the most advantageous for her torpedo barrages. Directly synergistic support for her is somewhat lacking, however; Bismarck provides some extra Crits, especially since Rupprecht currently has 0 Luck, and Brünhilde can buff her Accuracy somewhat.
As for full Iron Blood fleets?
Ägir is an exceptional Vanguard tank, suitable for pretty much anything, and her Skills benefit both Main Fleet styles (although she's a bit more suited to a gun line). Emden and Leipzig both provide buffs to her, although I don't put them both in the same fleet; I've found that makes the Vanguard a little too brittle, although it could just be confirmation bias. Instead, I prefer to put Mainz as the third ship to Ägir and Emden. The Main Fleet for those three is FdG, UvH, and Bismarck. Emden boosts everyone's firepower, Bismarck improves Crit Rates, Ägir slows and weakens the defenses of enemies. I use Mainz as my third ship because she's a bit faster than the other (heavy cruiser) options, and Magedeburg has similar durability problems as Leipzig. (This is actually the fleet I usually use for META fights.)
For a carrier fleet, my vanguard is typically Roon, Leipzig/Magdeburg, and Idol Roon/P-class. Emden doesn't buff carriers, since they don't use firepower. Ägir could be used to help them with the Slow, but they already have a Stop effect from August, and the Armor Break she provides helps the battleships more. That leaves Roon, Eugen, and the P-class sisters as suitable tanks. Eugen is out because she benefits a gunline more, like Ägir. I picked Roon because this is actually one of my OpSi fleets, and the extra damage against Sirens and MGM+1 appealed to me more than the not-actually-that-big increase in FP and Efficiency that the sisters get. (Also because I find Roon's personality less annoying than the sisters', but that's not nearly as big a deal.) Leipzig provides some offensive buffs and an increase in Speed for the vanguard, while Magdeburg gets barrages and progressive increases in damage dealt as the sortie goes on, but I'm not sure if she's actually doing better than Leipzig in a support role, so .... Unfortunately, Iron Blood doesn't have much support for its carriers; Bismarck and Peter Strasser are, IIRC, the only ships that have a direct buff for them.
In a Bismarck/Graf Zeppelin/August von Parseval fleet, the Vanguard would probably look much the same as the battleship fleet - Ägir, Emden or Leipzig, and Mainz. Without carrier-buffing ships, you just use good ones that work well together, and/or with Bismarck.
Blücher would probably do well in the first fleet as the third ship, or in the second fleet as either the second or third ship. I actually don't have her levelled to max yet, so I haven't played around with her too much. I also don't use destroyers unless there's something specific that needs them; Z1 and Z23 are both very good on their own, but despite their offensive advantages compared to some light cruisers, their brittleness is concerning and they don't add much to the fleet as a whole.
