So after repeatedly failing the champion's tournament, I decided to make a team that could win the pokémon World Tournament most of the time. This is what I came up with:

Dragonite@Lum Berry
Nature: Adamant
Ability: Multiscale

Moves: Dragon Dance
WaterFall
Firepunch
Outrage.

Evs: 204 Hp/ 252 Attack/ 52 spd

The ability and evs allow this guy to safely set up on Garchomp and Lapras and then sweep. I chose waterfall over Extremespeed as to have a move to KO Volcorona with without getting locked in. Fire Punch is for Metagross and Excadrill.

Vaporeon@Leftovers
Nature:Bold
Ability: Water Absorb

Moves: Surf
Ice Beam
Wish
Toxic

EVs: 248 Hp/ 252 Defense/ 8 Spd

This exists mainly to counter gyrados and Aerodactyl. Toxic gets some damage on Gyrados while wish allows it to stall. The Evs are to allow it to stay alive for as long as possible against the many physical attackers.

Chandelure@Focus Sash
Ability: Flash Fire
Nature: Timid

Moves: Shadow Ball
Energy Ball
Fire Blast
Hidden Power Ice

Evs: 252 Speed/252 Sp. Attack/4 Hp.

Standard Chandelure here. It's main job is to kill anything that is still alive at the end of the battle. Focus sash lets it survive boosted Garchomp and 1HKO with Hidden Power.