Please don't use sun in AG, or in any tier other than OU or ZU, where it is niche even there. Sun's abusers in AG are weak and bad, especially since you aren't running Growth on Venusaur or Shiftry.
Groudon
Groudon is a good Pokemon, but since Sun is not a good playstyle, that set is not good. I think it might, just might work if you slap on Lefties instead of Heat Rock, but Groudon is a great offensive threat and the final team wouldn't have a primary Dynamax abuser without it.
Groudon @ Life Orb
Ability: Drought
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Precipice Blades
- Stone Edge
- Aerial Ace
- Swords Dance
Venusaur --> Zekrom
As I've said before, Venusaur is pretty weak by AG standards. Dragon Dance Zekrom forms a nice pairing with Swords Dance Groudon, mainly for its good matchup against Ho-oh and Yveltal, while Don needs Stone Edge.
Zekrom @ Leftovers
Ability: Teravolt
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Bolt Strike
- Dragon Claw
- Substitute
- Dragon Dance
Heatran --> Marshadow
Zekrom and Groudon both struggle to break past defensive Lunala, however Marshadow doesn't have much trouble. Marshadow is also useful because of its synergy with another Pokemon on the team.
Marshadow @ Life Orb
Ability: Technician
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Poltergeist
- Close Combat
- Shadow Sneak
- Bulk Up
Slowbro --> Grimmsnarl
Slowbro is bad, especially on sun. Grimmsnarl will fit well here because of its Prankster Dual Screens enabling Marsh + Don + Zek, and because if you're desperate, you can use it to switch into defensive Lunala.
Grimmsnarl @ Light Clay
Ability: Prankster
EVs: 252 HP / 252 Def / 4 SpD
Impish Nature
- Reflect
- Light Screen
- Taunt
- Spirit Break
Blissey --> Landorus-Therian
Blissey is used as a Kyogre counter, but since this is hyper offense you don't need it. This slot can be replaced with Landorus-Therian, which is a nice suicide Stealth Rock lead for hyper offense.
Landorus-Therian @ Focus Sash
Ability: Intimidate
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Earthquake
- Stealth Rock
- Explosion
- Rock Tomb
Shiftry --> Kyogre / Calyrex-Shadow
Since sun is bad, Shiftry is also bad. This team lacks a Special Attacker. You can use Kyogre or Calyrex-Shadow, which are the best Special Attackers in AG. Some nerd found out Kyogre and Marshadow are really good together, with Kyogre beating Marshadow's checks and Marshadow beating Kyogre's checks. However, you can't go wrong with Calyrex-Shadow either.
Kyogre @ Choice Specs / Choice Scarf
Ability: Drizzle
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Water Spout
- Origin Pulse
- Ice Beam
- Thunder
Calyrex-Shadow @ Life Orb
Ability: As One (Spectrier)
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Astral Barrage
- Psyshock
- Nasty Plot
- Draining Kiss
