Agile Turtle: This is a very unique spread, appearing to prioritize bulk over offenses. I like the idea of a strictly-support set, though giving CAP 22 this much physical bulk may allow it to take on priority attackers better than it should. You should bolster the justification with some calcs against priority moves to show that it's not too much. Another concern is that with just 104 Special Attack, CAP 22 is going to have to rely on Focus Blast hitting multiple times.
The bulk is still nothing special, it allows us to take some hits better (most notably earthquake) but still doesn't give enough to handle anything it shouldn't. It still gets 2HKO'd by even an uninvested regular Scizor's Bullet Punch.
0 Atk Technician Scizor Bullet Punch vs. 0 HP / 0 Def Squirtle: 140-168 (54.4 - 65.3%) -- guaranteed 2HKO
Scizor is really the only one of the priority users listed in the threats discussion that doesn't carry anything it'd rather hit the CAP with insted of the weak base power priority move. Also Scizor pretty much never goes uninvested, even on the bulky sets it usually has a few EVs in attack. But even if Scizor does go uninvested, it's still enough to beat the CAP.
This is really the most that the CAP can do back to that Scizor:
252 SpA Life Orb Squirtle Focus Blast vs. 248 HP / 0 SpD Scizor: 263-309 (76.6 - 90%) -- guaranteed 2HKO
Banded Scizor OHKOs:
252+ Atk Choice Band Technician Scizor Bullet Punch vs. 0 HP / 0 Def Squirtle: 276-326 (107.3 - 126.8%) -- guaranteed OHKO
CAP vs the bulky SD set:
252 SpA Life Orb Squirtle Focus Blast vs. 248 HP / 200 SpD Scizor: 208-247 (60.6 - 72%) -- guaranteed 2HKO
44 Atk Technician Scizor Bullet Punch vs. 0 HP / 0 Def Squirtle: 146-174 (56.8 - 67.7%) -- guaranteed 2HKO
+2 44 Atk Technician Scizor Bullet Punch vs. 0 HP / 0 Def Squirtle: 288-342 (112 - 133%) -- guaranteed OHKO
Mega Metagross' Bullet Punch is also a 2HKO, but that's irrelevant when Metagross would rather opt for the OHKO with Meteor Mash, either way it takes one round of damage. Even against an HP-invested support EV spread CAP, the metagross OHKOs:
252 Atk Tough Claws Mega Metagross Meteor Mash vs. 252 HP / 0 Def Squirtle: 356-420 (111.2 - 131.2%) -- guaranteed OHKO
And this is the most CAP does back:
252 SpA Life Orb Squirtle Focus Blast vs. 0 HP / 0 SpD Mega Metagross: 200-238 (66.4 - 79%) -- guaranteed 2HKO
Azumarill's Aqua Jet was never anything this CAP would fear anyway, even on the band set, it still can't even 2HKO, but that's irrelevant when it would opt for play rough anyway.
252+ Atk Huge Power Azumarill Play Rough vs. 0 HP / 0 Def Squirtle: 306-362 (119 - 140.8%) -- guaranteed OHKO
And CAP can't even keep it from belly drumming:
252 SpA Life Orb Squirtle Moonblast vs. 92 HP / 0 SpD Azumarill: 208-246 (57.1 - 67.5%) -- guaranteed 2HKO
(this is the lowest that Azumarill ever runs in HP)
If Azumarill has already drummed though it doesn't matter because it's aqua jet is a OHKO:
+6 252+ Atk Huge Power Azumarill Aqua Jet vs. 0 HP / 0 Def Squirtle: 271-321 (105.4 - 124.9%) -- guaranteed OHKO
The support set I've intended for this CAP can potentially live the +6 Aqua jet
+6 252+ Atk Huge Power Azumarill Aqua Jet vs. 252 HP / 0 Def Squirtle: 271-321 (84.6 - 100.3%) -- 6.3% chance to OHKO
But this is all that does back:
4 SpA Squirtle Moonblast vs. 92 HP / 0 SpD Azumarill: 127-151 (34.8 - 41.4%) -- guaranteed 3HKO
Assvest Azu takesCAP on easy peasy:
252 SpA Life Orb Squirtle Moonblast vs. 240 HP / 16 SpD Assault Vest Azumarill: 136-161 (33.9 - 40.1%) -- guaranteed 3HKO
You mentioned some instances where Aura Sphere will be enough, but I encourage you to run more calcs with both Aura Sphere and Moonblast to make sure it's enough in more than just those limited scenarios. The same concern I have with david0895's mixed offenses somewhat resonate here; for example, are you expecting one of CAP 22's sets to take down the likes of Static Cyclohm and TankChomp with Play Rough? Overall, I'm not sure I understand this spread yet. I'll be sure to study it more closely over the week.
252 SpA Life Orb Squirtle Moonblast vs. 252 HP / 0 SpD Cyclohm: 463-549 (110.2 - 130.7%) -- guaranteed OHKO
252 SpA Life Orb Squirtle Moonblast vs. 252 HP / 0 SpD Tomohawk: 416-491 (100.4 - 118.5%) -- guaranteed OHKO
252 SpA Life Orb Squirtle Moonblast vs. 0 HP / 0 SpD Keldeo: 377-447 (116.7 - 138.3%) -- guaranteed OHKO
252 SpA Life Orb Squirtle Moonblast vs. 252 HP / 252+ SpD Revenankh: 234-276 (60.9 - 71.8%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Life Orb Squirtle Moonblast vs. 0 HP / 0 SpD Thundurus: 208-246 (69.5 - 82.2%) -- guaranteed 2HKO
252 SpA Life Orb Squirtle Moonblast vs. 252 HP / 4 SpD Quagsire: 243-289 (61.6 - 73.3%) -- guaranteed 2HKO after Leftovers recovery
Just a bunch of mons we're meant to beat with moonblast , we still manage just fine
252 SpA Life Orb Squirtle Aura Sphere vs. 252 HP / 192 SpD Ferrothorn: 218-260 (61.9 - 73.8%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Life Orb Squirtle Aura Sphere vs. 0 HP / 0 SpD Magnezone: 320-377 (113.8 - 134.1%) -- guaranteed OHKO
Pretty much anything else you might feel like hitting with aura sphere, close combat hits harder anyway, even uninvested CC vs invested aura sphere.
A lack of Focus Blast could make it struggle against Hippowdon, though:
252 SpA Life Orb Squirtle Moonblast vs. 252 HP / 112 SpD Hippowdon: 196-231 (46.6 - 55%) -- 12.5% chance to 2HKO after Leftovers recovery
But I'd say that's enough damage to deter it from trying staying anywhere near CAP, and tbh that's what you get for being a fighting type special attacker.
The mixed offenses aren't there for play rough, they're there so CAP can opt to run a more physically oriented mixed set to potentially be more threatening with close combat. Because close combat is a reliable high powered move, unlike focus blast which is unreliable, I believe that having the option to really do some threatening with an invested close combat is pretty helpful towards the concept. Mixed stats like these are pretty nifty, and so instead of the opponent bringing out their wall which can potentially be broken, they gotta bring out their plasmantas, venusaurs, Talonflames, Volcaronas, Tornadus-Therians, etc. All of which are the exact kinda of mons we want to debuff with parting shot.
And I mean play rough is a nice move and all, but moonblast is better in most scenarios for this CAP, I mean, play rough would be better than moonblast for things with higher special bulk than physical, like Revenankh, but again, for most scenarios moonblast is still better.
Also don't mistake this as me saying we should have this attack stat just because throwing around high powered close combats are scary. The option for a more physically oriented CAP22 has merit that allows us to beat some specific things on our list, such as Heatran.
252 Atk Life Orb Squirtle Close Combat vs. 252 HP / 0 Def Heatran: 400-476 (103.6 - 123.3%) -- guaranteed OHKO
A physically Oriented mixed set will do better on specially defensive heatran than a specially oriented set
252 SpA Life Orb Squirtle Focus Blast vs. 252 HP / 188+ SpD Heatran: 320-377 (82.9 - 97.6%) -- guaranteed 2HKO after Leftovers recovery
Which if want to at least have a chance at beating, is pretty important as an option, considering even uninvested, heatran still murders CAP with Flash Cannon
0 SpA Heatran Flash Cannon vs. 0 HP / 0- SpD Squirtle: 242-288 (94.1 - 112%) -- 68.8% chance to OHKO
Agile Turtle I appreciate the approach to this submission and think it is a noble goal to design a more support-oriented CAP, but I just shudder at the thought of another 600 BST CAP, especially one that somehow doesn't really stand out in any single area despite all those stats and such a high BSR. I'm still trying to wrap my head around how exactly the CAP would be played with these stats, so maybe you could shed some light on this for me (I doubt I'm alone on this, and before you say it, yes, I did read the entire submission).
I understand your apprehension with the base stat total, but I'll just go ahead and say that aurumoth's stats weren't what broke it. Sure they didn't help, but they aren't even a main factor in why it's overpowered. Also the CAP isn't super specialized in any specific way with the stats I desire on purpose, these stats are designed so the mon can be very versatile.
You have the main offensive set:
CAP22 @ Life Orb / Black Belt / Leftover
Ability: Natural Cure
EVs: 4 Atk / 252 SpA / 252 Spe
Naive Nature
-Focus Blast
-Moonblast
-Close Combat
-Parting Shot
The items are meant to be versatile depending on where you need this CAP to be on a Power vs Longevity scale.
This set has the wallbreaking potential it needs to coax those poison and fire mons in that it wants to debuff with parting shot.
Then you have a more physically oriented set:
CAP22 @ Life Orb
Ability: Natural Cure
EVs: 252 Atk / 4 SpA / 252 Spe
Naive Nature
-Close Combat
-Play Rough/Moonblast
-Focus Blast
-Parting shot
This set is very threatening with it's invested Close Combat, that not many things want to switch in to. Play Rough is there because on a more physciallly oriented set it makes more sense, but Moonblast is slashed on because it still handles things like garchomp better. Focus Blast is there because it's needed for the likes of Skarmory.
Then there is the support set:
CAP22 @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 4 SpA / 252 Spe
Naive Nature / Timid Nature
-Focus Blast
-Moon Blast
-Close Combat / Protect / ?
-Parting Shot
This set doesn't have power investmnet, and as such won't hit as strong but it still hits most of the things we'd like to handle, like Skarmory and Chansey, while it also fares better against more powerful things like garchomp. I imagine this set performing like a Kitsunoh support set, where it has max HP and Speed investment, and carries one or two support moves.
I'm not really sure if this is what you were looking for, though, but here.