Only reason this thread was bumped was because quite a few changes were made, and it's still not the best it can be.
So this is it. 4th Gen is coming to an end. And with that, my best 4th Gen team emerges.
After much testing with all of my teams, this had the greatest success overall.
Images by Arkeis.
Role: Azelf's role is to provide an excellent Special Attacking lead.
Moveset: This moveset allows for massive type coverage. Psychic is mainly for the occasional Gengar, and Machamp. Then Flamethrower is for some extra type coverage in general, mostly Ninjask. Grass Knot is great for Swampert leads, as it OHKO's with no problem. Finally, U-Turn is for other Psychic leads like Gallade and other Azelfs, along with providing a great way to switch.
EVs, Nature, and Item: The EVs give Azelf to OHKO almost anything. The Nature provides some speed which helps to outrun other Expert Belt leads. Finally, Expert Belt really helps since Azelf will almost always have a Super Effective move.
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Heatran (M) @ Shuca Berry
Ability: Flash Fire
EVs: 252 SpA/252 Spe/4 Def
Timid nature (+Spe,-Atk)
- Earth Power
- Flamethrower
- Hidden Power (Electric)
- Stealth Rock
Role: Heatran's role is to help provide a clean sweep along with providing one part of a FWG core. Heatran can also be used to take out other Heatrans, thanks to Shuca Berry.
Moveset: Earth Power allows for some very useful extra move coverage. As for Flamethrower, I find that it is much more useful than Fire Blast because of Heatran's massive SpA since Fire Blast has a lower accuracy. Hidden Power Electric is extremely useful when it comes to Gyarados, and this can OHKO after Stealth Rocks. And Stealth Rock is just a must for all teams now.
EVs, Nature, and Item: The EVs allow for massive damage, and a lot of Speed. Timid nature also helps a lot to get some much needed extra quickness. And as I said before, Shuca Berry allows to take out Agility Metagross and other Heatrans.
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Gyarados (M) @ Leftovers
Ability: Intimidate
EVs: 156 HP/72 Atk/96 Def/184 Spd
Adamant nature (+Atk,-SpA)
- Dragon Dance
- Stone Edge
- Taunt
- Waterfall
Role: Gyarados/Heatran combo is very common, because it works well. In this case, Gyarados's role is to complete a bulky sweep.
Moveset: This moveset allows for some great type coverage, along with being able to set up or cripple whatever comes in. +1 Waterfall, even on a bulky spread, can do a lot of damage. Stone Edge is very useful for taking out opposing Gyarados's along with the Flying type that comes in occasionally.
EVs, Nature, and Item: The EV's allow for some useful bulkyness, which allows Gyarados to get an attack off almost every time it comes in since it will most likely not be OHKO'd. The nature provides some extra attack which is needed since the Atk EVs aren't full. Then with all bulky Pokemon, leftovers is necessary.
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Breloom (M) @ Toxic Orb
Ability: Poison Heal
EVs: 4 HP/252 Atk/252 Spe
Jolly nature (+Spe, -SpA)
- Spore
- Seed Bomb
- Stone Edge
- Sky Uppercut
Role: Breloom's role is to provide an excellent sweeper and cripple the opponent using Spore.
Moveset: This moveset gives Breloom a lot of type coverage. Spore is very useful for forcing a switch or taking out a major threat to the team. Then Seed Bomb is great for taking out Suicune or Ground types. Stone Edge proved to be very useful, especially when facing Gyarados. And finally, Sky Uppercut can be used for Blissey which easily stalls this team.
EVs, Nature, and Item: EVs allow for great Speed and the Nature helps to increase that. Then the item helps to restore any HP Breloom lost.
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Flygon @ Choice Scarf
Ability: Levitate
EVs: 252 Atk/252 Spe/4 SpD
Jolly (+Spe, -SpA)
- Earthquake
- U-Turn
- Outrage
- Thunder Punch
Role: Provide a good Physical attacker along with a much needed Electric resistance.
Moveset: This moveset gives Flygon room to counter whatever it needs. Electric types are easily taken out by Earthquake, and Outrage is great for taking out Dragonite, which can be a pest. Then Thunder Punch is great for dealing with Gyarados, and finally, U-Turn allows for easy scouting.
EVs, Nature, and Item: The EVs, Nature, and item give Flygon the Speed and Attack it needs to do some massive damage.
---
Jolteon @ Choice Specs
Ability: Volt Absorb
EVs: 252 SpA/252 Spe/4 HP
Timid (+Spe, -Atk)
- Shadow Ball
- Hidden Power (Ice)
- Thunderbolt
- Signal Beam
Role: Provide a counter to a lot of threats to this team, along with a very powerful Electric move.
Moveset: This moveset gives Jolteon the type coverage it needs to come in on almost anything and OHKO it thanks to Choice Specs
EVs, Nature, and Item: The EVs and Nature give Jolteon a ton of Special Attack and Speed, then the Choice Specs just increases the Special Attack even more.
So this is it. 4th Gen is coming to an end. And with that, my best 4th Gen team emerges.
After much testing with all of my teams, this had the greatest success overall.
Images by Arkeis.
The Team
Azelf @ Expert Belt
Ability: Levitate
EVs: 252 SpA/252 Spe/4 Atk
Naive nature (+Spe, -SpD)
- Psychic
- Flamethrower
- Grass Knot
- U-Turn

Azelf @ Expert Belt
Ability: Levitate
EVs: 252 SpA/252 Spe/4 Atk
Naive nature (+Spe, -SpD)
- Psychic
- Flamethrower
- Grass Knot
- U-Turn
Role: Azelf's role is to provide an excellent Special Attacking lead.
Moveset: This moveset allows for massive type coverage. Psychic is mainly for the occasional Gengar, and Machamp. Then Flamethrower is for some extra type coverage in general, mostly Ninjask. Grass Knot is great for Swampert leads, as it OHKO's with no problem. Finally, U-Turn is for other Psychic leads like Gallade and other Azelfs, along with providing a great way to switch.
EVs, Nature, and Item: The EVs give Azelf to OHKO almost anything. The Nature provides some speed which helps to outrun other Expert Belt leads. Finally, Expert Belt really helps since Azelf will almost always have a Super Effective move.
---

Heatran (M) @ Shuca Berry
Ability: Flash Fire
EVs: 252 SpA/252 Spe/4 Def
Timid nature (+Spe,-Atk)
- Earth Power
- Flamethrower
- Hidden Power (Electric)
- Stealth Rock
Role: Heatran's role is to help provide a clean sweep along with providing one part of a FWG core. Heatran can also be used to take out other Heatrans, thanks to Shuca Berry.
Moveset: Earth Power allows for some very useful extra move coverage. As for Flamethrower, I find that it is much more useful than Fire Blast because of Heatran's massive SpA since Fire Blast has a lower accuracy. Hidden Power Electric is extremely useful when it comes to Gyarados, and this can OHKO after Stealth Rocks. And Stealth Rock is just a must for all teams now.
EVs, Nature, and Item: The EVs allow for massive damage, and a lot of Speed. Timid nature also helps a lot to get some much needed extra quickness. And as I said before, Shuca Berry allows to take out Agility Metagross and other Heatrans.
---

Gyarados (M) @ Leftovers
Ability: Intimidate
EVs: 156 HP/72 Atk/96 Def/184 Spd
Adamant nature (+Atk,-SpA)
- Dragon Dance
- Stone Edge
- Taunt
- Waterfall
Role: Gyarados/Heatran combo is very common, because it works well. In this case, Gyarados's role is to complete a bulky sweep.
Moveset: This moveset allows for some great type coverage, along with being able to set up or cripple whatever comes in. +1 Waterfall, even on a bulky spread, can do a lot of damage. Stone Edge is very useful for taking out opposing Gyarados's along with the Flying type that comes in occasionally.
EVs, Nature, and Item: The EV's allow for some useful bulkyness, which allows Gyarados to get an attack off almost every time it comes in since it will most likely not be OHKO'd. The nature provides some extra attack which is needed since the Atk EVs aren't full. Then with all bulky Pokemon, leftovers is necessary.
---

Breloom (M) @ Toxic Orb
Ability: Poison Heal
EVs: 4 HP/252 Atk/252 Spe
Jolly nature (+Spe, -SpA)
- Spore
- Seed Bomb
- Stone Edge
- Sky Uppercut
Role: Breloom's role is to provide an excellent sweeper and cripple the opponent using Spore.
Moveset: This moveset gives Breloom a lot of type coverage. Spore is very useful for forcing a switch or taking out a major threat to the team. Then Seed Bomb is great for taking out Suicune or Ground types. Stone Edge proved to be very useful, especially when facing Gyarados. And finally, Sky Uppercut can be used for Blissey which easily stalls this team.
EVs, Nature, and Item: EVs allow for great Speed and the Nature helps to increase that. Then the item helps to restore any HP Breloom lost.
---

Flygon @ Choice Scarf
Ability: Levitate
EVs: 252 Atk/252 Spe/4 SpD
Jolly (+Spe, -SpA)
- Earthquake
- U-Turn
- Outrage
- Thunder Punch
Role: Provide a good Physical attacker along with a much needed Electric resistance.
Moveset: This moveset gives Flygon room to counter whatever it needs. Electric types are easily taken out by Earthquake, and Outrage is great for taking out Dragonite, which can be a pest. Then Thunder Punch is great for dealing with Gyarados, and finally, U-Turn allows for easy scouting.
EVs, Nature, and Item: The EVs, Nature, and item give Flygon the Speed and Attack it needs to do some massive damage.
---

Jolteon @ Choice Specs
Ability: Volt Absorb
EVs: 252 SpA/252 Spe/4 HP
Timid (+Spe, -Atk)
- Shadow Ball
- Hidden Power (Ice)
- Thunderbolt
- Signal Beam
Role: Provide a counter to a lot of threats to this team, along with a very powerful Electric move.
Moveset: This moveset gives Jolteon the type coverage it needs to come in on almost anything and OHKO it thanks to Choice Specs
EVs, Nature, and Item: The EVs and Nature give Jolteon a ton of Special Attack and Speed, then the Choice Specs just increases the Special Attack even more.