I really like that question, Quilphish! I have used sun once or twice on Nollan's old serv and have some stuff to say about it.
The first thing that comes to mind when making a sun team in Skymons should probably be Jumpluff. Jumpluff's amazing support movepool and blistering speed allow it to effortlessly annoy the opposition with tools such as Sleep Powder, Encore, and Momento. And this is outside of the sun, mind you. In the sun, the majority of Choice Scarf Pokemon cannot catch it (idk Scarf Ninjask maybe?), and easily fall victim to it's Sub-Seeding shenanigans. It can run many viable sets in Skymons for the purpose of annoyance. These are my favorites of them:
Name: Utility
Jumpluff @ Leftovers
Trait: Chlorophyll
EVs: 252 HP / 4 Atk / 252 Spe
Jolly Nature
- U-turn
- Encore
- Sleep Powder
- Momento
Name: SubSeed
Jumpluff @ Leftovers
Trait: Chlorophyll
EVs: 252 HP / 4 Def / 252 Spe
Jolly Nature
- Encore
- Substitute
- Sleep Powder
- Leech Seed
Both of these sets work wonders when sun is employed, making this little cotton ball one hell of a burden to bulky offense teams and Heavy Offense teams alike.
Now of course, you're going to need some Pokemon to set up Sun. Thankfully, there are many, many Pokemon legal in Skymons with the ability to set up sun, the most prominent being Bronzong. While it may be odd to use Bronzong for sun, something that highlights its only weakness, Fire Type attacks are fairly uncommon in comparison to other attacking types in Skymons. Bronzong also has impeccable bulk, allowing it to set up screens, set up sun, set up Rocks. or attack whenever it wants. Here is the sets I like to use for Bronzong in sun:
Name: Sunny Day
Bronznog @ Heat Rock
Trait: Levitate
EVs: 252 HP / 4 Atk / 252 Def
Relaxed Nature
- Sunny Day
- Stealth Rock
- Toxic
- Gyro Ball
Name: SunnyScreens
Bronzong @ Heat Rock / Light Clay (I like to use Light Clay if I'm using Explosion, but Heat Rock's cool too.)
Trait: Levitate
EVs: 252 HP / 252 Atk / 4 Def
Adamant Nature
- Sunny Day
- Reflect
- Light Screen
- Explosion / Gyro Ball
Of course, there are many other viable setters of sun in Skymons, such as Aerodactyl, Charizard (though I prefer to use the Scarf variant in tandem with Sun support), Crobat, Cressalia, Drifblim (sounds weird, but trust me, it's actually pretty cool imo.), Gengar, Xatu, the Rotom Formes, Weezing, and Volcarona. That's just to name a few! But the most effective at what they do are the Pranksters; Volbeat, Illumise, and Murkrow. While it may be undesirable to use these presumably mediocre Pokemon on your team, they all have the ability to set up sun before any other Pokemon can, which is quite a cool thing to have on a dedicated weather team. All of the Lake Trio can also set up Sunny Day, iirc, so they are all also viable options.
Now, we have all these Sun setters, but what about the sun abusers? Well, there aren't as many sun abusers as setters, but all of them radiate raw power and easily dent the opposition thanks to their boosted STABs. Some of my favorites include Moltres, Charizard, and Volcarona, all of which have the ability to set up Sun on their own and wreck face, or apply a Choice item and demolish everything in sight with proper support. Other options for abusers include Azelf, the Lati Twins, and Rotom-H, who also pack plenty of raw power and a good enough move pool to see use. Here are sets for some of these Pokemon under the sun:
Name: Choice Scarf
Moltres @ Choice Scarf
Trait: Pressure
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Fire Blast
- U-Turn
- Hidden Power [Grass]
- Air Slash
Name: Life Orb
Latios @ Life Orb
Trait: Levitate
EVs: 252 SpA / 4 SpDef / 252 Spe
Timid Nature
- Draco Meteor
- Psyshock
- Hidden Power [Fire]
- Surf (For when sun is not active) / Recover
Name: Offensive Calm Mind
Latias @ Leftovers / Life Orb
Trait: Levitate
EVs: Really, they're interchangable. I'm just going with max/max to show off the sets :x . I would run maybe 96 HP / 160 SpA / 252 Spe
Timid Nature
- Calm Mind
- Dragon Pulse
- Hidden Power [Fire]
- Roost
Name: Specs Overkill
Charizard @ Choice Specs (interchangable with Scarf.)
Trait: Solar Power
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
- Fire Blast
- Focus Blast
- SolarBeam
- Air Slash
Name: Quiver Dance
Volcarona @ Leftovers
Trait: Flame Body
EVs: 252 HP / 252 SpA / 4 Spe (not the best spread, but w/e)
Modest Nature
- Quiver Dance
- Fire Blast
- Giga Drain
- Bug Buzz I'm retarded. For some reason I thought that Volc was legal, but clearly it isn't :x
So, all in all, I think sun is a very cool offensive playstyle in Skymons. It's also very challenging, as many of the sweepers are frail, but I find it to be really, really fun, nontheless.