For the PWT I used this strategy and Pokemon and it was very effective against a lot of trainers. Note*: this moveset and strategy works the best with rotation battles.:
Trait: Rough Skin
EV spread: 252 Atk. 252 Spe, 4 HP
-Dragon claw( STAB move+coverage against dragon trainers like Lance, Drayden,..)
-Sword Dance( boosts attack stat
-Earthquake( STAB+ coverage against ice types( good against Candice,... Counters steel, rock types( Trainers like Steven Stone
-Fire Fang( Counters steel, grass, ice)
Garchomp is an excellent sweeper. With its High speed and attack stat it can sweep a team when not treated correctly. I suggest you don't set up sword dance when battling any Dragon type trainers. Try to get them out immediately. I would say go for Dragon claw instead of Outrage because it is critical not to be locked into a Pokémon that resists dragon type attacks.
Rotom-W @ Leftovers
EV spread: 252 SpAtk. 252 Spe, 4 HP
-Volt switch(to scout if needed)/Thunderbolt( STAB+ counters flying, water types
-Hydro Pump/Surf( STAB+ Counters rock, ground, Fire
-Will-O-Wisp( To ware down foes)
-Shadow ball(Counters ghost type/Grass knot( to get water/ground threats such as gastrodon, swampert, quagsire down.
Rotom-W is a great Pokémon to use in the PWT. With it's great bulk and excellent movepool it is a real monster. Coupled up with garchomp it can take any hit that was meant for Garchomp, but beware of Outrage.
Metagross@ Steel Gem
Trait: Clear Body
EV spread: 252 Atk. 200 HP, 52 Spe.
-Bullet punch ( STAB+Priority move)
-Meteor Mash (STAB+ great power+ chances to raise attack stats)
-Zen headbutt(STAB+Great power and chance to flinch
With Garchomp and Rotom-W as it companions it is a great Pokémon to use for the rotation challenge. With it's great power and attack stat is light wall and physical Tank that does make a threat when not taken out soon enough
Latios @ White herb
EV spread: 252 Sp. Atk. 252 speed
-Hidden power (fire)
-Draco Meteor(TAB+Great Power, taks out dragon types for sure)
-Surf(Countes fire, ground, rock types)
-Psyshock(STAB+great power and countes specially defensive Pokemon well)
Latios sweeps for Garchomp in case Garchomp is taken out. With higher speed, Latios can truly reck havoc. It is not outsped by anything except for Cynthia's Scarfed Glaceon, and Red's quick claw Snorlax.
Scizor @ Flying Gem
EV spread: 252 Atk. 200 defense. 52 SpDe
-Acrobatics( With flying gem an technician it has great power)
-Bullet Punch( STAB priority move)
-Pursuit(To still b able to hit predictable switches
In Rotation battles Scizor works as a great support to Latias. Taking dragon type attacks very well and is capable of taking Bug, dark,ghost moves you can easily switch any threat to Latios in with Scizor. It's purpose is to finish unfinished business with it's powered-up priority moves
This team got me through the whole PWT. Hope it helpes you too