ADV NU

Threats To Prepare For (Offensive):
Arbok (CB, [RARE] Glare), Golbat (CB)
Bellossom (Fat SunnyBeam), Tangela (SunnyBeam), [RARE] Weepinbell (SunnyBeam)
Chimecho (CM)
Crawdaunt (CB, SpAttacker)
Diglett (CB)
Flareon (CB, Mixed), Torkoal (Mixed Exploder)
Graveler (CB), Pupitar (DD), Relicanth (CB), Sudowoodo (CB, SubPunch)
Haunter (Sub)
Hitmonchan (CB, Bulk Up), Machoke (CB, Bulk Up)
Huntail (Rain Dance Sweeper)
Kecleon (CB)
Kingler (CB, EndFlail)
Mawile (SDpass, SubPunch, [RARE] CB)
Metang
Murkrow (CB, [RARE] Mixed), Pidgeot (CB)
Octillery, Seadra
Pikachu, Plusle
Piloswine (Tank, CB, Screens), Whiscash (Tank, CB)
Raticate (CB, EndRev), [RARE] Furret (CB+Trick), Vigoroth (SubPunch, Bulk Up, EndFlail/Rev)
Swalot
Venomoth
Wailord (CurseBoom, CB, Mixed)

Threats Involving Trapping/Baton Pass:
Diglett (CB)
Flareon (CB, Mixed, Wish, always Dry)
Houndour (Pursuit)
Mawile (SDpass, [RARE] Iron Defense)
Minun (Agility/Screens/Wish), Plusle (Dry/Agility)
Venomoth (Dry, with Status moves), [RARE] Ariados (TrapPass), [RARE] Beedrill (Agility/SD), [RARE] Ledian (SD/Agility), [RARE] Volbeat (Tail Glow)
[RARE] Huntail
[RARE] Trapinch (CB)

Pokemon To Use On Offense:
Arbok (CB, [RARE] Glare), [RARE] Ariados (CB), Golbat (CB), [RARE] Seviper (CB, SpAttacker)
Cacturne (Spikes, SubPunch)
Chimecho (CM), [RARE] Abra
Crawdaunt (CB, SpAttacker)
Diglett (CB)
Flareon (CB, Mixed), Torkoal (Mixed Exploder)
Graveler (CB), Pupitar (DD), Relicanth (CB), Sudowoodo (CB, SubPunch)
Haunter (Sub)
Hitmonchan (CB, Bulk Up), Machoke (CB, Bulk Up)
Huntail (Rain Dance Sweeper)
Kecleon (CB, Status Platform)
Kingler (CB, EndFlail)
Mawile (SDpass, SubPunch, [RARE] CB)
Metang (CB, Agility, Screens)
Minun, Plusle
Murkrow (CB, [RARE] Mixed), Pidgeot (CB)
Octillery, Seadra
Pelipper
Piloswine (Tank, CB, Screens), Whiscash (Tank, CB)
Raticate (CB, EndRev), [RARE] Furret (CB+Trick), Vigoroth (SubPunch, Bulk Up, EndFlail/Rev)
Swalot
Tangela (SunnyBeam), [RARE] Bellossom (Offensive SunnyBeam), [RARE] Gloom (SunnyBeam), [RARE] Sunflora (SunnyBeam), [RARE] Weepinbell (SunnyBeam)
Venomoth
Wailord (CurseBoom, CB, Mixed)
[RARE] Beedrill (Swarm+Endeavour, CB)
[RARE] Clamperl
[RARE] Combusken
[RARE] Cubone
[RARE] Dragonair (DD), Shelgon (DD)
[RARE] Dunsparce
[RARE] Elekid
[RARE] Grovyle
[RARE] Houndour (Pursuit)
[RARE] Masquerain
[RARE] Mightyena (CB)
[RARE] Lairon (CB)
[RARE] Seaking (Swift Swim)
[RARE] Staryu (Spin)
[RARE] Yanma

Pokemon To Use On Balance:
Bellossom (Fat SunnyBeam), Tangela (SunnyBeam, PhysDef), [RARE] Tropius (SunnyPhaze), [RARE] Weepinbell (SunnyBeam)
Cacturne (Spikes, SubPunch)
Chimecho (CM, Bulky)
Crawdaunt (CB, SpAttacker)
Flareon (CB, Mixed, Wish), Torkoal (Mixed Exploder)
Graveler (CB), Pupitar (DD), Relicanth (CB, PhysDef, [RARE] Swift Swim, [RARE] CM), Sudowoodo (CB, SubPunch)
Haunter (Sub)
Hitmonchan (CB, Bulk Up, Spin), Machoke (CB, Bulk Up)
Kecleon (Status Platform)
Kingler (CB, EndFlail)
Lickitung (Full Cleric)
Mawile (SDpass, SubPunch, [RARE] CB)
Metang (CB, Agility, Screens)
Minun, Plusle
Octillery, Seadra
Pelipper
Piloswine (Tank, CB, Screens), Whiscash (Tank, CB)
Roselia (Spikes)
Sableye (Wall, CM)
Swalot
Vigoroth (SubPunch, Bulk Up)
Venomoth
Wailord (CurseBoom, CB, Mixed)
Whiscash
[RARE] Dustox (Phazer)
[RARE] Magcargo
[RARE] Parasect (Status Platform)
[RARE] Porygon
[RARE] Shedinja
[RARE] Shelgon (DD, Wish)
[RARE] Wigglytuff

Pokemon To Use On Stall:
Bellossom (Fat SunnyBeam), Roselia (Spikes, Cleric+Spikes), Tangela (PhysDef), [RARE] Tropius (SunnyPhaze), [RARE] Weepinbell (Fat SunnyBeam)
Chimecho (Bulky)
Dewgong
Flareon (CB, Mixed, Wish)
Hitmonchan (Rapid Spin)
Lickitung (Full Cleric)
Relicanth (PhysDef, [RARE] CM)
Sableye (Wall, CM)
[RARE] Chinchou
[RARE] Dustox (Phazer)
[RARE] Lileep
[RARE] Mightyena (Heal Bell+Phazer)
[RARE] Noctowl (Phazer)
[RARE] Shelgon (Wish)
[RARE] Wartortle (Spin)

Leads:
Flareon (CB, Mixed, Wish), [RARE] Charmeleon, [RARE] Magby, [RARE] Quilava, Torkoal (Mixed Exploder)
Glalie (Spikes)
Hitmonchan (CB, Spin)
Poliwhirl (SalacDrummer)
Relicanth (CB), Sudowoodo (CB)
Roselia (Spikes)

Hazard Control:
Cacturne (Spikes)
Glalie (Spikes)
Hitmonchan (Spin)
Roselia (Spikes)
[RARE] Anorith (SD Spin)
[RARE] Baltoy (Spin)
[RARE] Staryu (Spin)
[RARE] Wartortle (Spin)

Exploders:
Glalie (Spikes)
Graveler (CB), Sudowoodo (CB, SubPunch)
Metang (CB, Agility)
Swalot
Torkoal (Mixed Exploder)
Wailord (CurseBoom, CB, Mixed)

Cores:
Mawile+Diglett+Vigoroth/Raticate
Flareon+Sableye
Flareon+Bellossom+Whiscash

Base Speeds:
97 - Raticate
95 - Diglett, Haunter, Minun, Plusle
91 - Murkrow, Pidgeot
90 - Pikachu, Venomoth, Vigoroth
85 - Seadra
80 - Arbok, Glalie
76 - Hitmonchan
75 - Kingler
70 - Dewgong
65 - Chimecho, Flareon, Pelipper, Roselia
60 - Tangela, Wailord, Whiscash
55 - Cacturne, Crawdaunt, Relicanth, Swalot
52 - Huntail
51 - Pupitar
50 - Bellossom, Mawile, Metang, Piloswine, Sableye
45 - Machoke, Octillery
40 - Kecleon
35 - Graveler
30 - Lickitung, Sudowooodo
20 - Torkoal

Base Speeds (RARE mons included):
97 - Raticate
95 - Diglett, Elekid, Grovyle, Haunter, Minun, Plusle, Yanma
91 - Murkrow, Pidgeot
90 - Abra, Furret, Golbat, Pikachu, Poliwhirl, Venomoth, Vigoroth
85 - Ledian, Seadra, Staryu, Volbeat
83 - Magby
80 - Arbok, Charmeleon, Glalie, Quilava
75 - Anorith, Beedrill, Kingler
70 - Dewgong, Dragonair, Mightyena, Noctowl
68 - Seaking
65 - Chimecho, Dustox, Flareon, Houndour, Pelipper, Roselia, Seviper
60 - Masquerain, Tangela, Wailord, Whiscash
58 - Wartortle
55 - Baltoy, Cacturne, Combusken, Crawdaunt, Relicanth, Swalot, Weepinbell
52 - Huntail
51 - Pupitar, Tropius
50 - Bellossom, Mawile, Metang, Piloswine, Sableye, Shelgon
45 - Dunsparce, Machoke, Octillery
40 - Ariados, Gloom, Kecleon, Lairon
35 - Cubone, Graveler
32 - Clamperl
30 - Lickitung, Magcargo, Parasect, Sudowoodo, Sunflora
23 - Lileep
20 - Torkoal
10 - Trapinch

------ SOME SPECIFIC SETS! ------

(as a general note, Attack IVs are as minimised as they can be without affecting hidden powers (if relevant) in order to reduce confusion damage (more likely than struggle in this metagame), for Pokemon not otherwise using Physical Attacks)

-- Bulky Bell --
Bellossom (F) @ Leftovers
Trait: Chlorophyll
EVs: 252 HP / 32 SAtk / 144 SDef / 80 Spd
IVs: 2 Atk / 30 SAtk / 30 Spd
Calm Nature (+SDef, -Atk)
- Synthesis
- Sunny Day
- Solar Beam
- Hidden Power [Fire]

What it does:
The set and EV spread make it an effective counter (yes, counter!) to Huntail and Plusle. The Speed EVs allow it to outspeed Max Speed Base 91s under Sun (extra EVs can be spared or removed depending on your team's needs).
Plusle Hidden Power Ice vs. Bellossom: 91-108 (25.7 - 30.5%) -- 1.1% chance to 4HKO after Leftovers recovery
Huntail Ice Beam vs. Bellossom: 146-172 (41.2 - 48.5%) -- guaranteed 3HKO after Leftovers recovery
Huntail Ice Beam vs. Bellossom on a critical hit: 292-344 (82.4 - 97.1%) -- guaranteed 2HKO after Leftovers recovery!

-- Mixed Cash --

Whiscash (M) @ Leftovers
Trait: Oblivious
EVs: 252 HP / 28 Atk / 132 Def / 36 SAtk / 16 SDef / 44 Spd
Bold Nature (+Def, -Atk)
- Surf
- Earthquake
- Ice Beam
- Protect

Rest or Toxic could be fit if you want it.

Whiscash is a nice soft check to Birds, solid check to Plusle and Minun, and all-around solid Pokemon, well-suited for Balance teams, although it doesn't provide any specific team support or a win condition, and faces large competition from other Pokemon such as Piloswine and Relicanth. It also beats up on Arbok and Swalot somewhat nicely, Seviper less so due to its somewhat grand Special Attack stat which gives it more of a punch with Giga Drain than Arbok could ever hope to achieve.

(252+) Plusle Hidden Power Grass vs. Whiscash: 299-352 (70.5 - 83%) -- guaranteed 2HKO after 2 layers of Spikes and Leftovers recovery
Whiscash Earthquake vs. (252/0) Minun: 285-336 (87.9 - 103.7%) -- guaranteed OHKO after 1 layer of Spikes, 25% chance to OHKO without Spikes.
Whiscash Ice Beam vs. (4/0) Pidgeot: 154-182 (50 - 59%) -- guaranteed 2HKO
Choice Band Pidgeot Double-Edge vs. Whiscash: 212-250 (50 - 58.9%) -- 76.2% chance to 2HKO after Leftovers recovery, but much reduced when Protect is factored in. EVs can be taken from speed into defense to increase the resilience to these hits.

The Speed EVs outspeed 0 Speed base 65s (mainly Chimecho and Flareon), and EVs can be taken from Defense to increase the Speed, as suits the needs of the team. Note that if you run a Relaxed Nature, you require 32 Speed EVs to outspeed Min Speed base 55s (most notably, Relicanth and Swalot) - so often still running Brave may be optimal for your team.

-- Pursuit EndSalac Hound --

Houndour (F) @ Salac Berry
Trait: Early Bird
EVs: 36 HP / 252 SAtk / 8 SDef / 212 Spd
IVs: 2 Atk
Modest Nature (+SAtk, -Atk)
- Fire Blast
- Pursuit
- Endure
- Crunch

The primary objective of Houndour is to Pursuit-trap Haunter, as well as potentially do heavy damage to Chimecho, or check SunnyBeamers with its Fire/Grass resistances, vaguely passable bulk, and Early Bird.

The speed EVs allow it to outspeed the whole unboosted metagame after a Salac boost, as well as outspeed Max Speed base 50s before a Salac boost (notably including Bellossom, Mawile, Metang, and Piloswine). SpA is maximised for damage output, then with the remaining EVs, the HP EVs allow it to get down to Salac level using Spikes if need be (3 times of 3 layers of Spikes), with the rest thrown into its more useful defensive stat, SpD (Haunter, Chime, and Sunnybeamers are all Specially Offensive Pokemon). You could happily just throw those EVs all into Special Defense anyways since its Defense is fairly unsalvageable, and it's unlikely to come in and out so often as to be using Spikes to obtain a Salac boost.

-- CM Chimecho --

Chimecho (F) @ Leftovers
Trait: Levitate
EVs: 48 HP / 152 Def / 252 SAtk / 56 Spd
IVs: 3 Atk / 30 SAtk
Modest Nature (+SAtk, -Atk)
- Calm Mind
- Psychic
- Hidden Power [Electric]
- Substitute / Reflect

My EV (and IV) spread for CM Chime - it should be fairly clear as a Pokemon what it's meant to achieve however.

56 Speed allows it to outspeed 0 Spe Dewgong. The attack is maximised, and then the EVs are made such that it has as much HP as it can afford and still avoid the OHKO from CB Hitmonchan's HP Ghost.

Choice Band Hitmonchan Hidden Power Ghost vs. Chimecho: 239-282 (84.4 - 99.6%)

-- Bulky Flareon --

Flareon can run a hella-ton of sets and spreads; however most of them are ultimately more simple versions of this EV spread, or just max/max.

EVs: 248 HP / 52 Def / 72 SDef / 136 Spd
IVs: 0 Atk
Timid Nature (+Spd, -Atk)

Choice Band Mawile Rock Slide vs. Flareon: 282-332 (84.6 - 99.6%) -- guaranteed 2HKO
Choice Band Mawile Focus Punch vs. Flareon: 281-331 (84.3 - 99.3%) -- guaranteed 2HKO
Flareon Flamethrower vs. (252/0) Mawile: 317-374 (104.2 - 123%) -- guaranteed OHKO
Tangela SolarBeam vs. Flareon: 70-83 (21 - 24.9%) -- possible 5HKO after Leftovers recovery
Outspeeds Max Speed base 50s (unlikely to meet these however).
Rest in Special Defense to check Tangela as nicely as possible.

The variety of sets I've run or considered running includes:
Rest/Sleep Talk/Flamethrower/Roar - Sleep Absorbing + Phazing, requires no extra support to deal with Sleep or Sunnybeamers.
Flamethrower/Wish/Protect/Roar or Baton Pass or Quick Attack; functions as a Wish-passer, but can't handle Sleep super easily. The utility move of choice in the last slot depends on the team.
Flamethrower/Protect/Shadow Ball/Roar - interesting one I run, it's also heavily anti-Chimecho (and Haunter), and still requires no Attack investment to do decent damage (reflect will be frustrating though) - you may want to experiment with EV spreads for it though. It fits nicer on slightly faster-paced teams - it's too easily worn down by what it's meant to check for it to suit Stall, and Protect is an average form of recovery - but the scouting abilities are exemplary (it makes a nice lead though). HP Grass and Toxic are other notable moves on it.
Choice Band can work too, but probably wants a different EV spread.