This is a really good ingame team in Pokemon Sun & Moon. I'm playing on Moon so make a few changes if needed. Instead of Lunala, you have Solgaleo. Replace Magnezone with Vikavolt. These Pokemon are caught relatively early in the game except for the Legendary. If you don't want to use a legendary, catch a Psychic or Ghost type Pokemon like Alakazam or Gengar. Bagon can be caught at Kala'e Bay after getting so take the opportunity to get a Pseudo Legendary. You can use whatever items you want but I recommend Primarina Z to use Oceanic Operetta as it has 195 base power and Salamence Mega Stone. These are varied typing, each Pokemon has dual types. All move types are covered except Bug unless you can teach Magnezone Signal Beam or get a Vikavolt. If you have any other suggestions, feel free to leave a comment. Thanks for taking the time to view this post.
Primarina
Moves:
Moonblast
Sparkling Aria
Energy Ball
Ice Beam
Magnezone
Moves:
Thunderbolt
Hyper Beam
Flash Cannon
Thunder Wave
Lunala
Moves:
Moongeist Beam
Psychic
Night Daze
Calm Mind
Salamence
Moves:
Fire Fang
Dragon Claw
Earthquake
Aerial Ace
Muk
Moves:
Crunch
Poison Jab
Venom Drench
Rock Slide
Crabominable
*Ability: Iron Fist
Moves:
Ice Hammer
Earthquake
Power Up Punch
Dizzy Punch
Primarina
Moves:
Moonblast
Sparkling Aria
Energy Ball
Ice Beam
Magnezone
Moves:
Thunderbolt
Hyper Beam
Flash Cannon
Thunder Wave
Lunala
Moves:
Moongeist Beam
Psychic
Night Daze
Calm Mind
Salamence
Moves:
Fire Fang
Dragon Claw
Earthquake
Aerial Ace
Muk
Moves:
Crunch
Poison Jab
Venom Drench
Rock Slide
Crabominable
Moves:
Ice Hammer
Earthquake
Power Up Punch
Dizzy Punch