Shuca Berry Xurkitree + Waterium Z Latias

Swampert @ Leftovers
Ability: Torrent
EVs: 240 HP / 252 Def / 16 Spe
Relaxed Nature
- Stealth Rock
- Earthquake
- Scald
- Roar

Scizor @ Iron Plate
Ability: Technician
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Swords Dance
- Bullet Punch
- U-turn
- Roost

Mamoswine @ Life Orb
Ability: Thick Fat
EVs: 252 Atk / 4 SpA / 252 Spe
Naughty Nature
- Ice Shard
- Earthquake
- Icicle Crash
- Freeze-Dry

Xurkitree @ Shuca Berry
Ability: Beast Boost
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Tail Glow
- Thunderbolt
- Grass Knot
- Hidden Power [Ice]

Latias @ Waterium Z
Ability: Levitate
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Calm Mind
- Draco Meteor
- Psyshock
- Surf

Aerodactyl-Mega @ Aerodactylite
Ability: Tough Claws
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Stone Edge
- Wing Attack
- Earthquake
- Pursuit

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Mega Steelix + Sylveon + Vincune Balance

Steelix-Mega @ Steelixite
Ability: Sturdy
EVs: 248 HP / 8 Def / 252 SpD
Careful Nature
- Stealth Rock
- Heavy Slam
- Earthquake
- Roar

Sylveon @ Leftovers
Ability: Pixilate
EVs: 248 HP / 244 Def / 16 Spe
Bold Nature
IVs: 0 Atk
- Wish
- Protect
- Hyper Voice
- Hidden Power [Fire]

Tentacruel @ Black Sludge
Ability: Liquid Ooze
EVs: 208 HP / 108 SpA / 192 Spe
Timid Nature
IVs: 0 Atk
- Rapid Spin
- Scald
- Toxic Spikes
- Acid Spray

Gliscor @ Toxic Orb
Ability: Poison Heal
EVs: 248 HP / 72 Atk / 188 Spe
Jolly Nature
- Swords Dance
- Earthquake
- Facade
- Roost

Latias @ Electrium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Calm Mind
- Draco Meteor
- Psychic
- Thunder

Suicune @ Leftovers
Ability: Pressure
EVs: 252 HP / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Substitute
- Calm Mind
- Scald
- Protect

This is the closest I've come to making balance work in this meta since it "handles" Xurkitree.
Sylveon can run Heal Bell if Tentacruel runs Haze.
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Pursuit Mega Beedrill + Swords Dance Infernape Offense
Swampert @ Leftovers
Ability: Torrent
EVs: 240 HP / 252 Def / 16 Spe
Relaxed Nature
- Stealth Rock
- Earthquake
- Scald
- Roar

Empoleon @ Leftovers
Ability: Torrent
EVs: 240 HP / 248 SpD / 20 Spe
Calm Nature
- Defog
- Scald
- Knock Off
- Toxic

Celebi @ Groundium Z
Ability: Natural Cure
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Nasty Plot
- Giga Drain
- Psychic
- Earth Power

Infernape @ Life Orb
Ability: Iron Fist
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Flare Blitz
- Close Combat
- Thunder Punch

Hydreigon @ Choice Scarf
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Draco Meteor
- Dark Pulse
- Fire Blast
- U-turn

Beedrill-Mega @ Beedrillite
Ability: Adaptability
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- U-turn
- Poison Jab
- Drill Run
- Pursuit
I haven't tested this a ton, but it's been pretty fun to use. Not sure I'd trust it in a tour game without more practice.
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Alolan Muk + Entei Bulky Offense

Swampert @ Leftovers
Ability: Torrent
EVs: 240 HP / 252 Def / 16 Spe
Relaxed Nature
- Stealth Rock
- Earthquake
- Scald
- Roar

Muk-Alola @ Assault Vest
Ability: Poison Touch
EVs: 248 HP / 116 Atk / 144 SpD
Careful Nature
- Knock Off
- Pursuit
- Poison Jab
- Shadow Sneak

Entei @ Choice Band
Ability: Pressure
Shiny: Yes
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Sacred Fire
- Flare Blitz
- Extreme Speed
- Stone Edge

Scizor @ Iron Plate
Ability: Technician
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Swords Dance
- Bullet Punch
- U-turn
- Superpower

Latias @ Dragonium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Calm Mind
- Draco Meteor
- Psychic
- Recover

Aerodactyl-Mega @ Aerodactylite
Ability: Tough Claws
EVs: 216 Atk / 40 Def / 252 Spe
Jolly Nature
- Stone Edge
- Wing Attack
- Earthquake
- Aqua Tail

Built this to test Alolan Muk and Entei. It's been okay in practice, but struggles a bit to break stall. The Muk EV spread prevents Primarina from 2HKOing after Stealth Rock and ensures that Celebi doesn't KO with +2 Tectonic Rage.
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Crawdaunt + Sharpedo + Doublade Hyper Offense

Mamoswine @ Life Orb
Ability: Thick Fat
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Ice Shard
- Earthquake
- Icicle Crash
- Stealth Rock

Crawdaunt @ Waterium Z
Ability: Adaptability
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Swords Dance
- Crabhammer
- Knock Off
- Aqua Jet

Doublade @ Eviolite
Ability: No Guard
EVs: 248 HP / 252 Atk / 8 SpD
Adamant Nature
- Swords Dance
- Shadow Sneak
- Iron Head
- Sacred Sword

Latias @ Choice Scarf
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Draco Meteor
- Psychic
- Healing Wish
- Trick

Hawlucha @ Power Herb
Ability: Unburden
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Sky Attack
- High Jump Kick
- Acrobatics

Sharpedo-Mega @ Sharpedonite
Ability: Speed Boost
EVs: 252 Atk / 4 SpA / 252 Spe
Naive Nature
- Protect
- Crunch
- Hydro Pump
- Psychic Fangs

Fairly straightforward HO. Mamoswine can run Freeze-Dry. I forgot why Sharpedo is Hydro Pump, but feel free to make it whatever other move you want.
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Healing Wish Alomomola Offense

Nidoking @ Life Orb
Ability: Sheer Force
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Stealth Rock
- Earth Power
- Ice Beam
- Sludge Wave

Scizor @ Life Orb
Ability: Technician
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Swords Dance
- Bullet Punch
- Superpower
- Knock Off

Infernape @ Life Orb
Ability: Blaze
EVs: 168 Atk / 88 SpA / 252 Spe
Naive Nature
- Close Combat
- Overheat
- Grass Knot
- Gunk Shot

Alomomola @ Leftovers
Ability: Regenerator
EVs: 40 HP / 252 Def / 204 SpD / 12 Spe
Bold Nature
IVs: 0 Atk
- Wish
- Protect
- Scald
- Healing Wish

Latias @ Dragonium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Calm Mind
- Draco Meteor
- Psychic
- Hidden Power [Fire]

Sharpedo-Mega @ Sharpedonite
Ability: Speed Boost
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Protect
- Crunch
- Waterfall
- Psychic Fangs

I'm convinced that this is garbage, but Eyan won vs. Sabella with it, so either miracles do happen, Eyan is Jesus, or I'm just bad at using it.
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Nasty Plot Infernape + Calm Mind Reuniclus Bulky Offense

Swampert @ Leftovers
Ability: Torrent
EVs: 240 HP / 252 Def / 16 Spe
Relaxed Nature
- Stealth Rock
- Earthquake
- Scald
- Roar

Crobat @ Black Sludge
Ability: Infiltrator
EVs: 40 HP / 252 Atk / 216 Spe
Jolly Nature
- Brave Bird
- Taunt
- Defog
- Roost

Scizor @ Choice Band
Ability: Technician
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Bullet Punch
- U-turn
- Superpower
- Pursuit

Infernape @ Firium Z
Ability: Blaze
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Nasty Plot
- Fire Blast
- Focus Blast
- Vacuum Wave

Sceptile-Mega @ Sceptilite
Ability: Lightning Rod
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Leaf Storm
- Dragon Pulse
- Giga Drain
- Hidden Power [Fire]

Reuniclus @ Colbur Berry
Ability: Magic Guard
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Calm Mind
- Psyshock
- Focus Blast
- Recover

Haven't tested this yet but theoretically it'd work. Build ORAS, add Scizor.
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Tail Glow Xurkitree + Hawlucha Offense

Nidoking (M) @ Life Orb
Ability: Sheer Force
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Stealth Rock
- Earth Power
- Ice Beam
- Sludge Wave
Primarina @ Choice Specs
Ability: Torrent
EVs: 252 SpA / 252 Spe
Modest Nature
IVs: 0 Atk
- Hydro Pump
- Moonblast
- Scald
- Psychic

Scizor @ Choice Band
Ability: Technician
EVs: 252 Atk / 252 Spe
Adamant Nature
- Bullet Punch
- U-turn
- Superpower
- Pursuit

Xurkitree @ Electrium Z
Ability: Beast Boost
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Tail Glow
- Thunderbolt
- Grass Knot
- Hidden Power [Ice]

Hawlucha @ Power Herb
Ability: Unburden
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Sky Attack
- High Jump Kick
- Acrobatics

Aerodactyl-Mega @ Aerodactylite
Ability: Tough Claws
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Stone Edge
- Wing Attack
- Earthquake
- Pursuit

Really early post-drops team that originally had Nidoqueen over Nidoking before it became clear how useful Nidoking's speed tier was. I don't like it that much now, but it did well on the ladder.
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Work Up Pidgeot + Double Dance Terrakion Offense

Swampert @ Leftovers
Ability: Torrent
EVs: 240 HP / 252 Def / 16 Spe
Relaxed Nature
- Stealth Rock
- Earthquake
- Scald
- Roar

Scizor @ Choice Band
Ability: Technician
EVs: 252 Atk / 252 Spe
Adamant Nature
- Bullet Punch
- U-turn
- Superpower
- Pursuit

Celebi @ Leftovers
Ability: Natural Cure
EVs: 48 HP / 208 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Nasty Plot
- Giga Drain
- Psychic
- Hidden Power [Fire]

Terrakion @ Rockium Z
Ability: Justified
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Close Combat
- Stone Edge
- Rock Polish

Hydreigon @ Choice Scarf
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Draco Meteor
- Dark Pulse
- Fire Blast
- U-turn

Pidgeot-Mega @ Pidgeotite
Ability: Keen Eye
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Work Up
- Hurricane
- Refresh
- Roost

Another really early post-drops team that's still legal. Also did well on the ladder, but I'm not sure I'd trust it in a serious match. Included it anyway because it has technically brought results.