Crazy Sun
Yes I know this team looks like a total shitpost, but it's midnight and my brain doesn't work anymore. At least I am having bunch of fun with it in the ladder, so let me introduce you to the team:
Groudon is the main star, of course. Not much to talk about it, its just a bulky physical sweeper.
When I was thinking which Pokémon I would choose to abuse Groudon's Sun, I decided to go with Blacephalon. Blacephalon with the Choice Scarf outspeeds pretty much everything in the format, except Regieleki that does not want to go against Groudon. Mind Blown does stupid damage in Sun, and has some coverage moves in Shadow Ball and Solar Beam
Then, I started looking for a Flash Fire/Telepathy Pokémon so I could be less punished while I use Mind Blown, so I chose Coalossal as mostly a joke, but after messing around with it and with Steam Engine, I realized that +1 Coalossal's Heat Wave can deal massive damage to many threats on the format, so I decided on that. The Speed investement allows it to outspeed Regieleki at +6.
I was having issues regarding Urshifu-S, Urshifu-R and Rillaboom, and Fake Out could give me some problems as well, so I decided on Tsareena as my Grass-type, as it also has a good Kyogre matchup.
Gardevoir was a pick that I messed around with a bit and I really liked it, actually. What she is doing here is first of all, being the Telepathy Pokémon, alongside Helping Hand to further boost Blacephalon's damage, although it can also set Trick Room so Coalossal and Groudon can play slowly with their lacking Speed tiers. I closed off with Shadow Sneak to break Focus Sashes that could get in the way.
Last but not least, Zapdos job here is helping me with loose ties of the team, such as Zacian's matchup and also Kyogre's. Pretty standard set, outspeeds Urshifu by 1 point.
Watch this chaotic team in battle!
https://replay.pokemonshowdown.com/gen8vgc2021series10-1405325093