There's a lot wrong with the tank design, half of which comes from skills like rampart, where every tank needed to match that, along with not making cohesive enough skill sets to match the jobs original theme. so instead they took basic MMO mechanics from all roles/classes, and gave a bit of each to everyone. (Such as how they gave every job a DoT.)
One last feature isnt skill sets, but how every job goes through pretty much the same pattern of job quests. (This is less important, but is a bit disappointing.)
WAR is basically FF5 berserker with the FFXI left overs. (The name Warrior is not to be confused with the Fighter/Warrior/Knight jobs of old FFs, those were different jobs)
Considering it started from a semi pirate class, I feel MRD should have gone Viking instead.
That put to the side, berserk making WAR going into a rampage of spamming the same skill is pretty much as close as you can get to the actual berserk skill of FF5.
Over all, WAR is a bit of a mess when it comes to its skills/mechanics matching its original theme as a barbarian. Because of this, mixed with lack of prior FF options, im going to save WAR for semi-last, and return to it.
PLD is basically the FF1 Fighter>Knight, FF3 Knight (some FF3 magic knight themes), FF4 Knight (called PLD in the US to make it stand out from Dark Knight. Otherwise it would be weird if Dark Knight upgraded to Knight) FF5 Knight/Warrior, FF11 Knight (called PLD in the US)
Normally PLDs white magic is what makes it stand out, compared to the other strong melee types who can take strong physical hits decently. But due to game design, this isnt a very good feature, PLUS the possibility of future tanks (we wont get) that could use this for their own flavor.
So going with what we got, Sheltron/Shield mechanics seem to be best, since PLD is the only shield user for some reason. (This is for theme)
DRK's primary mechanic that is shared in all games, is to sacrifice HP to deal damage in a situational way. Be it adding more damage. Damage that ignore defense. Damage that is ranged (the most common) or damage that is AoE. (One of the few melees with AoE in most FF games)
There's 2 different ways to go about this, but changing it slightly.
(1) The only HP sacrifice is to TBN, lose 5% HP, to gain ~20+% hp shield. (This woulda been fine in HW/SB, but with current numbers, this isnt as effective)
(2) Abilities cost HP, but with darkside up, you convert the HP cost to MP. If you're out of MP, HP is lost instead. (But if darkside is still up, the damage gained is lowered slightly)
2 being better suited for DRKs main themes.
(Side Note: Id use the blood gauge instead of MP. MP seems kinda dumb when you have blood. Also MP usage as a mechanic is better suited for another tank. (That we wont get.))
GNB doesnt have much of a theme to work with from prior titles. So its kinda free to be w/e. I would personally go with more of a Rune Fencer/Runic Knight kinda build/style. (And a story about how they upgraded from being runic knights prior)
With the games current tanks in mind ONLY, this leaves mitigation mechanic themes for WAR and GNB.
WAR seems to be the stock standard physical armor tank. Since RNG block design went to PLD, and temp HP went to DRK.
I would focus more on the berserk system, and trying to keep your "rage" up as much as possible, w/o actually hitting the max 100 "rage". (Sorry for lack of better word) Once its a 100, you berserk. You have inner Release, which is best suited to stack with berserk, so you ideally dont berserk until inner release is up.
So I'd design WARs mitigation to be enhanced when your rage is at higher numbers. (This applies to all mitigation tools)
Hitting something hard (fell cleave) helps alleviate your anger, so WAR would be similar to what it is now.
Holmgang would be replaced with something more Berserk feeling. (kind of like living dead, except you can only spam one skill once in walking dead/zerk) but off hand im not sure how to balance this, so as nto to be too good of a DPS increase, so its not just used as soon as the battle starts, and on CD. (Only methods I can think of, require rebuilding how tanking works for all tanks, closer to WoWs design)
GNB I can only think of parry, for the fencer theme, and some sorta elemental shields for magic dmg. (currently DRKs theme... dunno why)
I honestly care very little about GNB, so I wont really bother theorizing ideas for it, when I feel so many more jobs can use the ideas I have thought up.
Back to PLD, its mostly fine as is, with the exception its filler mitigation doesnt incorporate blocking more.
Its MP is used offensively, rather than defensively, which I feel it should have had Protect/Shell as anti tank buster skills. (they only last a few seconds)
None of its skills should have been -X% of an enemies attacks, so as to balance the other methods of mitigation better. (such as absorbing dmg with blood bath. its not effective as mitigation, due to PLD making -dmg% too good by comparison)
Shields block dmg based on block strength. (which acts like their own defense) NOT a % of the enemies dmg!!!
DRK being the HP tank is fine, we dont need to add magic def/parry/eva tanking to DRK. DRK should revolve around HP. (this was mostly explained already)
This leaves room for a lot of future tank ideas, w/o stacking them on the current tanks we have.
Such as a tank built around a convalescence type of mechanic. Self healing/absorbing tank. Evasion tank (this requires the biggest change to how tanking is handled). and some other mechanics i mentioned in other threads, where i listed every possible method of mitigating dmg in unique ways. (MMOs have only scratched probably half of whats possible, maybe less)
Lastly, the difference in the tanks should be based on;
(1) what is the bare minimum required for a fight? now add 1 extra option to each tank, for one of the requirements. (example: 3 magical tank busters, 3 physical. all tanks can handle 2 magical, but only one can hand the 3rd, while the same for physical. tank swapping effectively also handles this, but it helps make tanks "feel" a bit more unique. Other types of dmg are possible, but again requires some changes to combat design)
(2) Ratio of "Threat", "Filler Mitigation", "TB/invuln mitigation", "CC/support", and "DPS" being roughly equally capable, but different in difficulty to perform. (Example: 1 tank generates threat easily, so easily, they never even look at the threat. But they have to actively maintain mechanics to keep their basic suitability up, more so than other tanks. Another tank survives rather easily, only has to watch TBs, but spends most of the fight fighting to keep threat up.)
Once all of that is redesigned, THEN we can attempt to really fix whats going on with the tanks atm.
Otherwise, we're just adding band-aid fixes. With superfluous differences, like Sentinel vs Vengeance.
(Side note, we lack a lowered GCD tank, which I feel is better suited for 1hander tanks. Plus a DNC like tank, which does less direct dmg, but enhances the DPS of the other tank.)
Plus going into details on my opinions, followed by further opinions i hold, would take multiple pages worth of text. I've already typed up a lot, and said so little.
Pretty much agree. BUT, if we're to ever have an evasion tank, invulns would help balance out an evasion tank. (yet again, requires a lot of changes. plus my eva tank isnt some speedy thf or nin style job)
But if no evasion tank, i say get rid of most invulns, and just make them very potent mitigation, that still allows for death.
Absorb mechanics do seem to fit DRK thematically the best, but realistically, thats not always a DRK specialty.
Its been far more common in BLM.
Over all, If I were to give a tank the absorb theme, its hard not to think of the "Black Magic Knight" as the best candidate, which I feel is uneeded with the temp HP build I feel is best suited for DRK. (To fit the -hp mechanic only DRK has)
But I guess a Sorcerer/Mystic Knight could be next with an "Absorb Blade"/"En-Absorb" spell. (Which I said was closer to that of GNB. Yet again, GNB seems to just be a mixture of things, rather than having an identiy, which is why I hate it lol.)
I actually felt this way on the rage spenders. They can be performed at 0 rage, but have much higher GCDs as penalties. (To increase the feel of a large 2handed weapon)