Crobat: @ Black Sludge
104 HP / 152 Atk / 252 Spe
Jolly nature
Taunt
Roost
Brave Bird
U-Turn
Grants Poison types a nice Immunity to Ground. Being a lead helps it deal with Stealth Rock, mainly by preventing it from being set up in the first place... U-turn scouts for incoming Psychic, Ice, Rock or Electric types coming in. Drapion, Tentacruel, and Venasaur make great switch ins for those types in that same order.
Drapion: @ Black Sludge
252 HP / 12 Atk / 244 SpD
Careful nature
Battle Armor
Protect / Crunch
Pursuit
Earthquake
Swords Dance
Seems odd to combine a Swords Dance set with a [Specially] bulky EV spread, but ultimately it's designed for it. Drapion comes in on Psychic, Ghost, Dark moves that Target your teammates like Gengar and Pursuits them if they have STAB on either of the first two types. Protect is mainly for Explosion, incase Heatran, Azelf, or others that fear a KO by Drapion want to take him down with them, although Whirlwind also works well to force switches to aid Toxic Spikes. Earthquake is what prevents Heatran, Tyranitar, and Steels in general from overriding your teammates. Oh yeah, Gengar and Tentacruel helps with that too.
Additionally, Drapion is designed to take Special Attacks, with Timid Life Orb Gengar 3hkoing it at best with Focus Blast; don't expect Azelf to be KOing Drapion anytime soon either on the Special side.
Weezing @ Black Sludge
252 HP / 252 Def / 4 SpA
Bold
Dry Skin
Fire Blast
Thunderbolt
Will-O-Wisp
Pain Split
Hits Steels; Scizor, Gyarados, Heracross, Breloom, etc. with Fire Blast, and Thunderbolt, while Will-O-Wisp handles things like Machamp, if not already Poisoned.
Provides EQ Immunity, now only 2 Pokemon weak to Ground!
Weezing was pretty much necessary on my team for its unique Typing+Ability, and Special Attacks. W-o-w is just a bonus!
Venasaur @ Black Sludge
Natural Cure
Nature: Calm
252 HP / 252 SpD / 4 Spe
-Sleep Powder
-Leech Seed
-Grass Knot
-Hidden Power Fire / Sludge Bomb
Added in to handled Swampert, previously it was a very specific TSPikes Roserade. Sleep will help with spreading around status, while also giving Venasaur a chance to lay down some Leech Seed the switch in. Max SPD/HP is for survivability, while Hidden Power Fire hits Steels, but Sludgebomb hits Celebi, and Shaymin harder, while still hitting Abomasnow for nearly as hard as Hidden Power Fire would.
Tentacruel: @ Black Sludge
Liquid Ooze (anti-leech seed)
252 HP / 120 Def / 136 SpD
Calm
Toxic Spikes
Ice Beam
Hydro Pump (always better to have)
Rapid Spin
Works well with Gengar since it not only blocks Rapid Spinners, but also takes any Earthquakes directed to Tentacruel. Tentacruel in turn helps wear down Bulky Waters for Venasaur to come in on and finish off, or Gengar with Thunderbolt to finish off. Hydro Pump is when fighting Infernape and Heatran, any bulky ground types like Hippowdon, whilest Ice Beam handles whatever it can such as Celebi (whom is hurt by Leech Seed).
Gengar @ Black Sludge / Expert Belt
4 HP / 252 SpA / 252 Spe
Timid
Levitate
Substitute
Shadow ball
Focus Blast
Thunderbolt / Hidden Power Fire
Fool foes into thinking you have a Focus Punch set, whilst you really have max Special Attack and Focus Blast for those Physically Defensive steels (like Heatran). Substitute also allows Gengar to worry less about Pursuit and Priority users. Speaking of Pursuit and Priority users, Gengar can KO Scizor behind a Substitute with HP Fire, if it decides to forgo Thunderbolt. Thunderbolt is first choice, however, due to the many Water types (Gyarados, Vaporeon, etc.) that plague many Balanced and Defensive teams.
Overall, here is a balanced team that provides diverse type coverage, and can switch into eachother's weaknesses with ease. There are Defensive Pokemon like Tentacruel and Venasaur whom help take resisted Special hits, whilest there are Revenge Killers and late game sweepers like Drapion, and Gengar to finish things off. Crobat's U-turn provides ample scouting and Taunt really aids its anti-lead premise, while Venasaur is an overall staller, coming in on predicted Water attacks, and going for the status to force switches. Additionally, Rocks and Steels are dealt with by Gengar, Weezing, & Tentacruel to an extent, while there is still Drapion for finishing them off with Earthquake. Additionally, opposing Trick users are dealt with by switching in my Pokemon such as Gengar using it to sweep, or other Pokemon holding Black Sludge, which can cause 12.5% damage each turn on the foe, furthering forced switches and mind games. Remember, since it's mono-poison, you don't have to worry about any non-poisons getting Tricked back Black Sludge.
PREVIOUS TEAMMATES-
Where Weezing is now [After Toxicroak]
Roserade @ Black Sludge
Natural Cure
Nature: Timid
EV's: 6 SpD/ 252 HP/ 252 Spe
-Sleep Powder
-Leaf Storm
-Hidden Power Fire
-Toxic Spikes
Added in to handled Swampert, previously it was a very specific Scarf Nidoking. Sleep will help with spreading around status, while also giving Roserade a chance to lay down some Spikes on an opponents switch out. Max Speed/HP is for survivability, while outspeeding foes and sleeping them.
Attacks for coverage. HP Fire is also for Lucario.
--
Toxicroak @ Life Orb
4 HP / 252 Atk / 252 Spe
Jolly
Dry Skin
Swords Dance
Cross Chop
Sucker Punch
Stone Edge
Jolly is used simply for out speeding Adamant Lucario, and other Pokemon within that Speed range that use a neutral nature. Stone Edge is used over Ice Punch to handle Gyarados, as Toxicroak makes an excellent switch into Waterfalls, additionally Latias can be hit with Sucker Punch, and Salamence can be hit with Stone Edge for decent damage factoring in Swords Dance. Flygons, whilest seen, are likely either Jolly Banded, or Adamant Scarfed, outspeeding Toxicroak either way, leaving Ice Punch less useful than Stone Edges' hits on other flying types like Zapdos, as well as nuetral coverage.
Nidoking @ Choice Scarf
252 Atk / 112 SpA / 144 Spe
Naughty nature
Rivalry
Earthquake
Megahorn
Ice Beam
Fire Blast
With Choice Scarf, Nidoking outspeeds Timid Azelf, and KOs with Megahorn, as well as +Speed natured Scarf Tyranitars.
Don't bother with outspeeding Weavile, as soon as the cover is blown Weavile will just switch out or Ice Shard Nidoking. Nidoking also needs all the power it can get, and sacrificing more Special Attack really hinders his last 2 slots, so much so that he has to use Rivalry to make up for his lack of Life Orb.
Nidoking lures out Water, Ice, Psychic, and Ground types, or at least Pokemon carrying those types of moves. As far as that's concerned, Toxicroak, Tentacruel, Drapion, Crobat and Gengar all handle at least one of those types with their own resistance or Immunity. But don't worry, Nidoking pulls his own wait, revenge killing Psychic and Dark Pokemon that try to kill Gengar with his own Megahorn.
Fire Blast handles Scizor, Forretress, Skarmary, etc., while Ice Beam handles Salamence, Gliscor, and others. Megahorn handles Celebi, and Earthquake is general STAB.
104 HP / 152 Atk / 252 Spe
Jolly nature
Taunt
Roost
Brave Bird
U-Turn
Grants Poison types a nice Immunity to Ground. Being a lead helps it deal with Stealth Rock, mainly by preventing it from being set up in the first place... U-turn scouts for incoming Psychic, Ice, Rock or Electric types coming in. Drapion, Tentacruel, and Venasaur make great switch ins for those types in that same order.
Drapion: @ Black Sludge
252 HP / 12 Atk / 244 SpD
Careful nature
Battle Armor
Protect / Crunch
Pursuit
Earthquake
Swords Dance
Seems odd to combine a Swords Dance set with a [Specially] bulky EV spread, but ultimately it's designed for it. Drapion comes in on Psychic, Ghost, Dark moves that Target your teammates like Gengar and Pursuits them if they have STAB on either of the first two types. Protect is mainly for Explosion, incase Heatran, Azelf, or others that fear a KO by Drapion want to take him down with them, although Whirlwind also works well to force switches to aid Toxic Spikes. Earthquake is what prevents Heatran, Tyranitar, and Steels in general from overriding your teammates. Oh yeah, Gengar and Tentacruel helps with that too.
Additionally, Drapion is designed to take Special Attacks, with Timid Life Orb Gengar 3hkoing it at best with Focus Blast; don't expect Azelf to be KOing Drapion anytime soon either on the Special side.
Weezing @ Black Sludge
252 HP / 252 Def / 4 SpA
Bold
Dry Skin
Fire Blast
Thunderbolt
Will-O-Wisp
Pain Split
Hits Steels; Scizor, Gyarados, Heracross, Breloom, etc. with Fire Blast, and Thunderbolt, while Will-O-Wisp handles things like Machamp, if not already Poisoned.
Provides EQ Immunity, now only 2 Pokemon weak to Ground!
Weezing was pretty much necessary on my team for its unique Typing+Ability, and Special Attacks. W-o-w is just a bonus!
Venasaur @ Black Sludge
Natural Cure
Nature: Calm
252 HP / 252 SpD / 4 Spe
-Sleep Powder
-Leech Seed
-Grass Knot
-Hidden Power Fire / Sludge Bomb
Added in to handled Swampert, previously it was a very specific TSPikes Roserade. Sleep will help with spreading around status, while also giving Venasaur a chance to lay down some Leech Seed the switch in. Max SPD/HP is for survivability, while Hidden Power Fire hits Steels, but Sludgebomb hits Celebi, and Shaymin harder, while still hitting Abomasnow for nearly as hard as Hidden Power Fire would.
Tentacruel: @ Black Sludge
Liquid Ooze (anti-leech seed)
252 HP / 120 Def / 136 SpD
Calm
Toxic Spikes
Ice Beam
Hydro Pump (always better to have)
Rapid Spin
Works well with Gengar since it not only blocks Rapid Spinners, but also takes any Earthquakes directed to Tentacruel. Tentacruel in turn helps wear down Bulky Waters for Venasaur to come in on and finish off, or Gengar with Thunderbolt to finish off. Hydro Pump is when fighting Infernape and Heatran, any bulky ground types like Hippowdon, whilest Ice Beam handles whatever it can such as Celebi (whom is hurt by Leech Seed).
Gengar @ Black Sludge / Expert Belt
4 HP / 252 SpA / 252 Spe
Timid
Levitate
Substitute
Shadow ball
Focus Blast
Thunderbolt / Hidden Power Fire
Fool foes into thinking you have a Focus Punch set, whilst you really have max Special Attack and Focus Blast for those Physically Defensive steels (like Heatran). Substitute also allows Gengar to worry less about Pursuit and Priority users. Speaking of Pursuit and Priority users, Gengar can KO Scizor behind a Substitute with HP Fire, if it decides to forgo Thunderbolt. Thunderbolt is first choice, however, due to the many Water types (Gyarados, Vaporeon, etc.) that plague many Balanced and Defensive teams.
Overall, here is a balanced team that provides diverse type coverage, and can switch into eachother's weaknesses with ease. There are Defensive Pokemon like Tentacruel and Venasaur whom help take resisted Special hits, whilest there are Revenge Killers and late game sweepers like Drapion, and Gengar to finish things off. Crobat's U-turn provides ample scouting and Taunt really aids its anti-lead premise, while Venasaur is an overall staller, coming in on predicted Water attacks, and going for the status to force switches. Additionally, Rocks and Steels are dealt with by Gengar, Weezing, & Tentacruel to an extent, while there is still Drapion for finishing them off with Earthquake. Additionally, opposing Trick users are dealt with by switching in my Pokemon such as Gengar using it to sweep, or other Pokemon holding Black Sludge, which can cause 12.5% damage each turn on the foe, furthering forced switches and mind games. Remember, since it's mono-poison, you don't have to worry about any non-poisons getting Tricked back Black Sludge.
PREVIOUS TEAMMATES-
Where Weezing is now [After Toxicroak]
Roserade @ Black Sludge
Natural Cure
Nature: Timid
EV's: 6 SpD/ 252 HP/ 252 Spe
-Sleep Powder
-Leaf Storm
-Hidden Power Fire
-Toxic Spikes
Added in to handled Swampert, previously it was a very specific Scarf Nidoking. Sleep will help with spreading around status, while also giving Roserade a chance to lay down some Spikes on an opponents switch out. Max Speed/HP is for survivability, while outspeeding foes and sleeping them.
Attacks for coverage. HP Fire is also for Lucario.
--
Toxicroak @ Life Orb
4 HP / 252 Atk / 252 Spe
Jolly
Dry Skin
Swords Dance
Cross Chop
Sucker Punch
Stone Edge
Jolly is used simply for out speeding Adamant Lucario, and other Pokemon within that Speed range that use a neutral nature. Stone Edge is used over Ice Punch to handle Gyarados, as Toxicroak makes an excellent switch into Waterfalls, additionally Latias can be hit with Sucker Punch, and Salamence can be hit with Stone Edge for decent damage factoring in Swords Dance. Flygons, whilest seen, are likely either Jolly Banded, or Adamant Scarfed, outspeeding Toxicroak either way, leaving Ice Punch less useful than Stone Edges' hits on other flying types like Zapdos, as well as nuetral coverage.
Nidoking @ Choice Scarf
252 Atk / 112 SpA / 144 Spe
Naughty nature
Rivalry
Earthquake
Megahorn
Ice Beam
Fire Blast
With Choice Scarf, Nidoking outspeeds Timid Azelf, and KOs with Megahorn, as well as +Speed natured Scarf Tyranitars.
Don't bother with outspeeding Weavile, as soon as the cover is blown Weavile will just switch out or Ice Shard Nidoking. Nidoking also needs all the power it can get, and sacrificing more Special Attack really hinders his last 2 slots, so much so that he has to use Rivalry to make up for his lack of Life Orb.
Nidoking lures out Water, Ice, Psychic, and Ground types, or at least Pokemon carrying those types of moves. As far as that's concerned, Toxicroak, Tentacruel, Drapion, Crobat and Gengar all handle at least one of those types with their own resistance or Immunity. But don't worry, Nidoking pulls his own wait, revenge killing Psychic and Dark Pokemon that try to kill Gengar with his own Megahorn.
Fire Blast handles Scizor, Forretress, Skarmary, etc., while Ice Beam handles Salamence, Gliscor, and others. Megahorn handles Celebi, and Earthquake is general STAB.