I've liked most sets submitted so far! I think that they show the different ways that CAP 24 can be used in both weather very well. That being said, I'd like to bring one point that most people have included in their sets without much considerations: Recovery moves. It seems that most people believe that having Shore Up/Synthesis is a necessity for CAP 24. However this seems to ignore how recovery makes CAP 24 exponentially harder to take down, and makes it job as a sun setter much easier, as we will be able to maintain our health through the game, and set up Sunlight as many times as needed. It should be noted that very few weather setter have access to recovery moves, and the ones that do still have clear weaknesses that CAP 24 lacks (For example, Pelipper has low base stats and is weak to SR, Hippowdon is extremely slow and passive, Malaconda is slow and a massive momentum sink for its own team, thanks to its x4 weakness to U-Turn and Mega-Charizard-Y consumes your Mega slot and is x4 weak to SR), which in turn means that there's no precedent to how such a powerful setter would affect the metagame.
Therefore, I believe that we should take very seriously whether of not should CAP 24 have access to Recovery moves. If you do support them, I'd like you to clearly explain why do you believe they are necessary for CAP 24 to work.
Now, for comments on more specific sets:
Name: Drought Abuser
Move 1: Moonblast
Move 2: Flamethrower / Weather Ball
Move 3: Focus Blast
Move 4: Synthesis / Healing Wish
Ability: Drought
Item: Life Orb / Fightinium Z / Heat Rock
EVs: 4 HP / 252 SpA / 252 Spe
Nature: Timid
Probably the most "standard" set submitted so far, I think that it is the most natural fit on a Sun core consisting of Heatran/Volkraken/CAP 24. I also appreciate the balance between offensive moves and support options presented, Healing Wish in particular is a very interesting choice, as it allows us to keep momentum and fully heal a teammate, but in exchange for CAP 24 life, which makes it a very high-risk/High-reward move. If I had to nitpick something, I'd consider adding Rapid Spin as an option on the second slot alongside Flamethrower/Weather Ball
Name: Stun Spore Savagery
Move 1: Moonblast
Move 2: Flamethrower
Move 3: Stun Spore
Move 4: Shore Up
Ability: Trace/Drought
Item: Leftovers
EVs: 252 HP/4 SpA/252 Spe
I'm not too fond of Stun Spore. While it is true that is completely useless against more defensive teams, it can seriously cripple almost any offensive check, like M-Crucibelle, M-Charizard-Y and Scarf Volkraken, and while its accuracy it's not great, it can still do its job most of the time.
I'd like to hear more on why would CAP 24 need a Paralysis spreading move.
Name: Sand Tank
Move 1: Moonblast
Move 2: Focus Blast
Move 3: Flamethrower
Move 4: Shore Up / Hidden Power Ice
Ability: Trace
Item: Leftovers / Fightinium Z
EVs: 144 HP / 148 SpA / 216 Spe
Nature: Modest / Timid
A more dedicated Sand support set, I like its ability to reliably deal with Tomohawk. However I think that Rapid Spin should be slashed alongside Focus Blast. Sand teams might already have a decent spinner in Excadrill, but it would still appreciate being able to have more flexibility with its moves.
Name: Sun Scarf
Move 1: Moonblast
Move 2: Flamethrower
Move 3: Focus Blast
Move 4: Hidden Power Ice / Healing Wish / Solar Beam
Ability: Drought
Item: Choice Scarf
EVs: 252 SpA / 4 SpD / 252 Spe
Nature: Timid / Modest
A Scarf set is definitely an interesting option, as CAP 24 has a great speed tier for one, being able to barely surpass the ubiquitous 95 tier by just one point. I'm not very convinced that HP Ice is necessary, as we already hit x4 weakness to Ice (like Zygarde, Garchomp and Landorus-T) already takes a ton of damage from our moves anyways, so I think that Solar Beam or Healing Wish are much better moves for your last slot. It should also be noted that a scarf set that loses against Cawmodore could be a problem for your own team, and requires additional support.
Name: Utility
Move 1: Moonblast
Move 2: Flamethrower / Focus Blast
Move 3: Rapid Spin / Heal Bell / Healing Wish
Move 4: Synthesis / Shore Up
Ability: Drought / Trace
Item: Heat Rock / Eject Button / Leftovers
EVs: 252 HP / 4 SpD / 252 Spe
This seems like a decent option, as it can provide support on both weathers, either by reliably providing Sun or by taking on threats that Sand teams can't usually handle. I am not sure if we need Heal Bell, as it seems rather excessive, specially alongside other powerful utility moves like Healing Wish and Rapid Spin. I'd also like to remove Eject Button as an item choice, as it is rather gimmicky and almost always will end up outclassed by Heat Rock/Leftovers
Name: Hazard Remover
Move 1: Moonblast
Move 2: Flamethrower / Focus Blast
Move 3: Rapid Spin
Move 4: Synthesis / Shore Up
Ability: Drought / Trace
Item: Heat Rock / Life Orb / Leftovers
EVs: 252 SpA / 4 SpD / 252 Spe
Nature: Timid
As its own set, this one doesn't really convince me at all, because it tries to combine both Sand and Sun on the same set. If you are using Drought, this is just a small variation on snake's set. If you use it with Trace, I think you would want to invest more in bulk, as that ability is better suited for defensive use, and offensive set miss the boosted Fire Coverage. However I agree that Hazard Removal is a very useful option for CAP 24.
Name: Fast Assault Vest
Move 1: Moonblast
Move 2: Giga Drain
Move 3: Fiery Dance
Move 4: Weather Ball / Focus Blast / Rapid Spin
Ability: Trace
Item: Assault Vest
EVs: 40 HP/212 SpA/8 SpD/248 Spe
Nature: Calm
Name: AV Resetter for Sand
Move 1: Moonblast
Move 2: Giga Drain/Leaf Storm
Move 3: Weather Ball/Flamethrower
Move 4: HP Ground/HP Ice
Ability: Drought
Item: Assault Vest
EVs: 236 HP/212 SpA/60 SpD
Nature: Calm
Assault Vest is an interesting item for CAP 24, but I'm not very sold on it, especially if we assume we're going to have reliable recovery. This is specially true in DK set, because with the same EVs and without AV, you still avoid the 2HKO from Celesteela's Flamethrower (0 SpA Celesteela Flamethrower vs. 40 HP / 0 SpD Tapu Bulu: 134-158 (40 - 47.1%) -- 0.4% chance to 2HKO after sandstorm damage) so you should be able to regain back your health with Shore Up, while still being able to use other items and Non-Attacking move. For this reason, I'd like to ask you both this question:
Why would CAP 24 sacrifice its item slot and possibly reliable recovery in exchange for the SpD boost that AV provides?
Also I do not like Fiery Dance at all. Even if we ignore the dubious optics of potentially giving CAP 24 two different Signature moves, this move would allows us to potentially break past some of checks with ease, most notably enabling Grassium-Z sets to OHKO Toxapex after a boost (+1 252+ SpA Tapu Bulu Bloom Doom (190 BP) vs. 248 HP / 252+ SpD Toxapex: 277-327 (91.4 - 107.9%) -- 50% chance to OHKO) For this reason, while it might be unreliable, it should not be included in our final movepool.
I am adding Fiery Dance to the list of banned moves
On a final note,
I will also add Knock Off to the list of disallowed moves. While Chansey will probably be able to counter CAP 24 even after losing its Eviolite, it's ability to reliably answer to other threats would be hampered, and this is not something we should be doing.