Healers, then and now:

[Renathras]

Next up, SCH:

In Stormblood, SCH's DPS kit consisted of the following:

Broil II - Standard nuke. Upgrade path from Ruin, Broil.
Ruin II - A stand-alone side-grade from Ruin, potency equal with Ruin, so DPS loss vs Broil I/II. Lower MP cost than Broils (higher than Ruin 1) but instant cast. Useful for movement or OOM periods. Could be used as a oGCD weaving tool. [0/situational casts per minute]
{Bio (I) - Instant cast DoT, 40 potency over 18 sec duration. [3.33... casts per minute on average.] } (Directly upgraded into Bio II, from all I can tell, as of 4.0)
Bio II - Instant cast DoT, 35 potency over 30 sec duration. Standalone in HW, but now direct upgrade. Lower potency, longer duration. [2 casts per minute]
Miasma - Cast time DoT, 24 sec duration. [2.5 casts per minute on average.]
Miasma II - AOE "spam" spell...but only just. 100 potency + 20 over 12 sec (4 ticks) 5 yard AOE instant cast, but cost 1680 MP. DPS loss vs Broil on single target (so not part of the standard rotation/situational casts per minute), but DPS gain over Ruin 2 if you were close to the boss and needed movement and also had an overabundance of MP (if you did not, Ruin 2 was the preferred choice). Mainly shoehorned into an AOE damage spamnuke since SCH didn't have Art of War at the time. [0/situational casts per minute]
(oGCD) Shadow Flare - Free, instant, oGCD, ground targeted, 15 sec duration field effect DoT with a 60 sec CD. NOT A GCD, so did not change the GCD button use.
(oGCD) Bane - 1 AF cost, instant, oGCD, spread existing DoTs from target to enemies within 8y. 10 sec self-CD. Obviously not used in single target fights.
(oGCD) Energy Drain - 1 AF cost, instant, oGCD, 150 potency attack. Used for MP management or AF stack dumping.
(oGCD) [Debatable] Dissipation - 180 sec CD, increases cast time healing spells and grants 3 AF.
(oGCD) Chain Strategem - 120 sec CD, increases crit chance against the debuffed target by 15% for 15 sec.
(oGCD) Cleric Stance - 90 sec CD to increase damage, Role Action (when you could only choose 5) that was sometimes not taken if fights required the other things instead (which were Protect, Divine Seal, Lucid Dreaming, Surecast, Swiftcast, Esuna, Rescue, Eye for an Eye, and Break; meaning this Cleric Stance wasn't even always a given.)

Selene also had 3 abilities that have somewhat been lost, all oGCDs:

(oGCD) Silence - 1 sec Silence, as noted in the write-up, this was essentially never ever used anyway.
(oGCD) Fey Caress - AOE Esuna on a 20 sec CD. Also essentially never used.
(oGCD) Few Wind - 3% attack, cast, and recast speed for 30 seconds. Generally used pre-pull and then not touched again (Eos and Selene had different AI, and Eos's was so much better people almost never used Selene), but potentially useful for speed kills. I thought this was folded into ShB's Fey Illumination, but I can't find that ability tooltip at the moment, so I'll have to dig more later. In any case, an extra DPS buff, but haste wasn't always considered useful (just like today) since it messes with people's rotations and alignment. Still, this could be thought of as ROUGHLY equivalent to New SMN's Searing Light, I suppose?

I also like this description of Dissipation from the author of what was clearly a VERY pro-"Green DPS"/Healers should do damage author, kind of amusing considering our discussions here recently of the ability and that, even back then, pro-damage SCHs were poo-pooing it:

Ruthlessly murder your fairy in exchange for 3 stacks instantly. Also grants you a 30 second buff that increases your healing by 20% for the next 30 seconds. However, you are unable to summon your fairy during that time.
I would say this skill is debatable. I personally do not know a single Scholar that uses it, and I do not use it myself. I would say it’s good for that extra tiny amount of damage if you don’t need the fairy for the next 30 seconds, or if you ran out of stacks for some reason and absolutely need one right now. That second scenario shouldn’t happen unless something went terribly wrong though. Trading the fairy just doesn’t seem worth it to me.

So that was then, time for now:

Endwalker SCH:

Broil IV - Spam nuke, now only 1.5 sec cast allowing for weaving Upgrade path of Ruin, Broil, Broil II, Broil III.
Ruin 2 - Same as before, situational use instant cast movement tool. Same MP cost as Broil (but 100 more than Ruin I), so no longer an MP conservation tool. No longer needed for SINGLE weaves, as Broil IV allows single weaves. [0/situational casts per minute]
Biolysis - DoT with a 30 sec duration. Unlike WHM's, doesn't have up front damage so is NOT a movement tool. Directly analogous to Bio II in SB. [2 casts per minute]
Art of War II - Instant cast AOE spamable centered on the caster. Actually does more damage than the other Healers' AOEs (vs Holy's 140/150 and Gravity's 120/130, it does 165/180); Miasma 2 replacement, does NOT do more damage than Ruin 2.
(oGCD) Energy Drain - 1 AF cost AF dump, does 100 potency of damage (50 less than SB), does some healing but does not generate MP (it did in ShB, but that was folded into the Aetherflow button itself)
(oGCD) [Debatable] Dissipation - 180 sec CD, increases cast time healing spells and grants 3 AF.
(oGCD) Chain Strategem - 120 sec CD, increases crit chance against the debuffed target by 15% for 15 sec.

SCH had some "intangibles" change, like better pet AI and more responsive pets, and gained additional healing tools like Seraph and a magic damage reduction on Fey Illumination, making it the undisputed king of mitigation and oGCD healing. However, it's clear it lost things from its kit. UNLIKE WHM, though, which substituted more frequent DoT reapplication for Afflatus GCD casts, SCH got no Lily abilities to fill dead GCDs with, creating a net change. Let's have a look:

Bio II had the same cadence as Biolysis today, so we can consider that in parity. 30 sec duration vs 30 sec duration, nothing really to discuss. The big changes (to the GCD cadence) were the following:

Miasma 2.5 casts per minute were removed.

Ruin II at least 1 cast per minute was removed (I say "at least" since even with 2x natural Bio II refreshes for AF oGCD weaves, you'd need one more. Remember that Broil at this time did not allow weaving without clipping. It would be more than 1 per minute if you were needing to weave more things). Ruin II was also niche useful as a MP management tool owing to the lower MP cost vs Broil III, something that is not shared with EW's Ruin II vs Broil IV. "At least" 1 is due to needing to burn at least 3 AFs per minute (for Faerie Gauge - lol - if nothing else, and obviously burning with ED since you don't want to leave that potency on the table), though this could be higher depending on whether or not you were able to use natural Bio II refreshes for oGCD weaves and that SCH also has a lot of OTHER oGCD weaves besides just AF.

Miasma II was a single target loss against Broil III and only situational as a replacement for Ruin II for movement or weaves. So we can say it's here, but it kind of also wasn't EXACTLY part of the GCD cadence and is more properly looked at, in a general sense, as a wonky version of Art of War. Still, you could trade that "at least 1 cast per minute" from Ruin 2 down here for hyper-optimization. The MP cost was so prohibitive that this would often be passed up for Ruin II anyway.

...short list, but actually more significant than it seems. As I noted above, unlike WHM, there were no replacements for these "at least" 3.5 GCDs per minute, so they were shunted to additional Broil casts. Broil IV allowing oGCD weaves also removed Ruin II/Miasma II's use in single target situations away from being optimal parts of the rotation and an MP management tool for Ruin 2 into being situational for heavy movement (in the case of Ruin 2) or high levels of oGCD weave needs, and in the case of Miasma II, being shunted to a strictly AOE role in the form of Art of War. So while "at least" 3.5 stands, in practice, it was probably closer to 6 assuming weaving 2-3 oGCDs per minute.

Note that this is largely an EW change, not a ShB one, since using Ruin II for oGCD weaves was still commonplace in ShB due to Broil's longer cast time. Broil's shorter cast time today is what really changed things for SCH honestly more than anything else, since Miasma I's removal aside, it altered how many Ruin IIs were used in the standard/general rotation for BOTH weaving AND movement - a 1.5 sec Broil IV allows for a lot more slidecasting, which can handle all but the longest distance and longest duration movements.

Unlike WHM, which filled those "dead" GCDs with 2.66... Afflatus abilities in ShB and now 4 in EW, SCH not only replaced the missing 2.5 Miasma casts with Broil IV, but it also replace a lot of the situational Ruin II and Miasma II casts with Broil IV, compounding the problem even more. And unlike WHM, which got better from ShB to EW, SCH actually GOT WORSE.

I'm not even sure I need to go into the oGCD kit, since I think the above already shows an outright massive change and glaring problem, but for the sake of completeness, SCH also lost (in short summary):

(oGCD) Shadow Flare - 1 weave per minute even on single target (free damage).
(oGCD) Bane - AOE/trash packs only, approximately 1 weaves per minute.
(oGCD) Few Wind - Highly situational, but an option for speed runners or optimizers. 1 cast per minute/60 sec CD.

It only actually lost one use on CD 1/min oGCD, one optional 2 (ish) per min oGCD (in practice, Bane was "the AOE Energy Drain" if you REALLY think about it), and a highly situational and largely unused 1/min Fey Wind. And sure, Cleric, whatever (at this point, recall it's just a slight buff once per minute used on CD...riveting...)

But if we are thinking in terms of "breaking up the monotony of Broilspam", the actual culprit here ISN'T any of that.

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The actual issue seems to be the removal of Miasma, Miasma 2/Art of War no longer having any use (even situational) in single target fights, and Ruin 2 having a MUCH reduced presence with Broil's shorter cast time.

oGCDs don't affect GCD cadence (for obvious reasons), and since collectively everyone discounts oGCDs (no one counts Assize or using Tetra as "breaking up Glarespam", so the only time ED or the like should count is if Broil has to be substituted with Ruin 2/Miasma 2 to cast them; that substitution is the actual break in the GCD Broilspam, not the oGCD weave), isn't the actual issue.

Indeed, it seems Broil's shorter cast time and Art of War not having single target applications are actually the big changes here. Broil's shorter cast means no need to switch up spells for oGCD weaves most of the time, and slidecasting is a stronger movement utility, removing as much need for casting Ruin 2 instead of Broil. Add in Art of War not being a single target gain over Ruin 2 and you basically eliminate everything other than the two natural Bio refreshes per minute.

Huh...

SCH's Broilspam is actually worse than WHM's Glarespam?

....

Checks out. Top SCH on Proto-Carbie has 148 Broil casts (with 14 Bios, 2 Ruin IIs, and 1 Adlo GCD heal) vs the top WHM having 141 (with 15 Dias and 6 Misery just under 7 min fight, 18 Raptures and no other GCD heals). SCH uses more oGCDs, but if we're talking about the Broilspam/Glarespam, Broilspam is actually...worse.

And doubly so since SCH before had more non-Broil buttons it was hitting (even ignoring oGCDs) than WHM had non-Stones...

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Funny, but looking at SCH actually makes me think EVEN MORE that WHM in EW is actually the best WHM has ever been... o.O At the VERY least, EW WHM is a step up from SB WHM and from ShB WHM.