Okay, so I made it to 1400 with my team, but I think this is as far as I'll get with it. I'll just post it here in case someone can improve upon it.
Weavile (Tsareena) @ Wide Lens
Ability: Queenly Majesty
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Triple Axel
- Knock Off
- U-turn
- Power Whip
My Triage counter and general physical hitter. Wide Lens for reliably hitting Triple Axels. Moveset is standard except for Power Whip in place of High Jump Kick, which I initially tried but found underwhelming (plus there are a bunch of Ghost types running around). Power Whip hits Rhyperior, Keldeo, Urshifu-Rapid, Primarina, etc. harder than your other moves.
Toxapex (Emolga) @ Leftovers
Ability: Motor Drive
EVs: 252 HP / 4 Def / 252 SpD
Relaxed Nature
IVs: 0 Spe
- U-turn
- Roost
- Defog
- Nuzzle
My usual lead (or anti-lead, I guess?). It spreads Paralysis and Defogs entry hazards. 0 Speed IVs and Relaxed nature so it gets off a slow U-Turn even with Paralysis' speed drop/Motor Drive's speed boost.
Cobalion (Orbeetle) @ Leftovers
Ability: Frisk
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Sticky Web
- U-turn
- Iron Defense
- Body Press
After 1 Iron Defense, this thing takes even super-effective hits surprisingly well. Sticky Web is there to slow down mons that my Toxapex can't Paralyze (notably Zeraora and Jolteon). U-Turn to gain momentum vs Ghost types that come in expecting Body Press, the latter of which is very strong as mentioned earlier in this thread.
Chandelure (Mawile) @ Life Orb
Ability: Sheer Force
EVs: 252 SpA / 4 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Flamethrower
- Shadow Ball
- Focus Blast
- Substitute
Pretty straight-forward wallbreaker set. The three attacks have perfect neutral coverage, so I gave it Substitute to deal with status users and to ease prediction. I'm on the fence about switching to Timid, just so I can guarantee outspeeding Zeraora with webs on the opponent's side.
Mandibuzz (Wooper) @ Heavy-Duty Boots
Ability: Unaware
EVs: 252 HP / 24 Def / 232 SpD
Impish Nature
IVs: 0 Atk
- Haze
- Recover
- Toxic
- Encore
My answer to set-up mons. Encore-lock them, Haze them, Toxic stall them, whatever it takes to not immediately lose to a Quiver Dancing Gengar or an Unburden+Swords Dance Gyarados. EV spread and Nature are just to have equal defenses.
Zeraora (Conkeldurr) @ Flame Orb
Ability: Guts
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Bulk Up
- Thunder Punch
- Close Combat
- Knock Off
I think this is the next best thing to the Mawile-donor set (which I can't run due to donor clause) in terms of immediate power.