I based this team around potential sweepers hampered by poor speed, and using a well-supported Ninjask to give them a useful boost. This is the team that has changed the most out of all the teams I made, because it is so hard to get right. In fact, the only remaining member of this team I made months ago is Ninjask. After changing it dozens of times, this is where I am now:
This doesn't mean that I'm done changing my team. Because this team still has problems, despite being my best result yet. However, this is only as far as I can get myself. Anyway, let me explain each member's role:
Ninjask @ Leftovers
Adamant
Speed Boost
258 HP / 8 Atk / 184 Def / 68 Spe
-Protect
-X-Scissor
-Substitute
-Baton Pass
X-Scissor gets some extremely useful quick KO's, and even some full HP 2HKOs, like on Roserade. I know some people that don't use an attack move on Ninjask, but that just doesn't work. One advantage this Ninjask has over the Swords Dance variant is Protect, which I am not sure how the Swords Dance Ninjask can survive without it. It lets Ninjask live longer via Leftovers, and prevents TrickScarf leads from working, Jirachi in particular. This Ninjask is bulky enough to survive mocst priority attacks and come back in later for more speed passing.
Synergy:
ExtremeSpeed - Aggron, Heatran, Rotom
Bullet Punch - Heatran, Starmie, Rotom
Ice Shard - Aggron, Heatran, Starmie
Mach Punch, Vacuum Wave: Heracross, Starmie, Rotom
Heracross @ Wide Lens
Adamant
Guts
252 Atk / 252 Spe / 4 SpD
-Swords Dance
-Megahorn
-Close Combat
-Night Slash
The first of my speed-receiving sweepers. Wide Lens is the only way I can use Megahorn, because I have absolutely terrible luck with accuracy. For instance, I once missed twice in a row with a Lens-boosted Aqua Tail, at 99 accuracy, not even against Gliscor in Sandstorm or Froslass in Hail. I chose Night Slash over Stone Edge to deal with Ghosts that resist both Megahorn and Close Combat. It is more useful overall, but leaves me useless against Zapdos (and obviously Gliscor, the Heracross counter).
Synergy:
Fire - Heatran, Starmie
Psychic - Aggron, Heatran, Starmie
Flying - Aggron, Heatran, Rotom
Aggron @ Wide Lens
Adamant
Rock Head
4 HP / 252 Atk / 252 Spe
-Head Smash
-Earthquake
-Aqua Tail
-Magnet Rise
252 Speed EVs is to not leave me completely useless without a Speed boost. Once again, Wide Lens is the only way I can use this set. Once, I got the Wide Lens Tricked away, and I missed with Head Smash right away and lost the battle. Originally I had Tyranitar here, but only because Head Smash wasn't appearing on Aggron's move list. Sandstorn was bad for my Ninjask, however, so I found a way to get Head Smash back using the online team builder. Aqua Tail is strictly for when rock is not very effective AND water is supereffective - even resisted Head Smash is more powerful. Earthquake seems surprisingly weak, but then again I usually use it either with STAB or a more powerful Pokemon. I only use Magnet Rise when I predict a Ground attack, because he is fast enough to pull it off and dodge the attack after a speed increase.
Synergy:
Ground - Ninjask, Heracross, Rotom and Magnet Rise
Fighting - Ninjask, Heracross, Starmie, Rotom
Water - Starmie
Heatran @ Life Orb
Rash (+SpA, -SpD)
Flash Fire
4 Atk / 252 SpA / 252 Spe
-Flamethrower
-Earth Power
-Hidden Power Grass
-Explosion
Scarf without Choice. When Ninjask is getting attacked by a Fire attack, I can pass 3 or 4 speed boosts and get a Flash Fire boost. This sweep is potentially game-ending. If not, it is definitely game-changing. When Blissey gets in my way, Explosion KOs. I hate having to resort to this, but it is worth it to get rid of her. Occasionally I will Explode on Dragonite, Salamence and Flygon, because they resist my attacks and I cannot allow them to sweep. Other than Dragonite and Salamence, I cannot think of anyone off the top of my head who resists Fire+Ground+Grass.
Synergy:
Ground - Ninjask, Heracross, Rotom
Fighting - Ninjask, Heracross, Starmie, Rotom
Water - Starmie
Starmie @ Leftovers
Timid
Natural Cure
136 HP / 156 Def / 216 Spe
-Rapid Spin
-Thunderbolt
-Surf
-Recover
I don't really like Starmie, but I couldn't think of a better choice for Rapid Spin support. In trying to keep my Ninjask alive, I had to choose between Wish and Rapid Spin support, as there are no Pokemon who learn both. I've tried using both Wish and Rapid Spin, but there is no room for two support Pokemon, and I've tried using just Wish, but Ninjask was harder to keep alive without Rapid Spin. So I settled with just Rapid Spin, but lack of Wish is pretty harsh.
Unless they're accompanied by Stealth Rock or Spikes, I won't spin Toxic Spikes - the only member they hurt is this Starmie (whom it would be too late to Spin because he is already poisoned), and they are arguably beneficial for Heracross, making it a short-lived but extremely powerful sweeper.
Synergy:
Dark - Heracross, Aggron, Heatran
Ghost - Aggron, Heatran
Bug - Heracross, Aggron, Heatran, Rotom
Grass - Ninjask, Heracross, Heatran
Electric - Rotom (slightly problematic)
Rotom-C @ Life Orb
Modest
Levitate
6 HP / 252 SpA / 252 Spe
-Thunderbolt
-Shadow Ball
-Leaf Storm
-Hidden Power Ice
What I needed for my final sweeper was immunity to Aggron's (and Heatran's) huge Ground and Fighting weakness, and someone who resists Electric attacks, which I lack elsewhere. Rotom-A fit this role perfectly, of course. I didn't spend too much time on deciding which forme to use; and to be honest, I am not sure if this one is the best choice. Leaf Storm is powerful and occasionally very useful, but I have to switch afterward, losing my speed boosts. I am considering switching to the Fan forme, which I use in my most powerful OU team and it works very well. That would give me an answer to Machamp, and Breloom (I would probably need Chesto Berry for this). HP Ice is my only Ice attack unfortunately, and is strictly for the 4x weak Gliscor, Dragonite, Salamence, and Flygon.
Synergy:
Dark - Heracross, Aggron, Heatran
Ghost - Aggron, Heatran
Threats:
Certain variants of pretty much anything can cause problems for this team. But these threats are ones that I noticed were recurring and could always cause trouble:
Despite being destroyed by two members of my team, Skarmory causes problems with Whirlwind, obviously. Even if I get Heatran or Rotom in, Skarmory will just switch out and come back later for more phazing. Skarmory also OHKOs my Heracross with Brave Bird, but I have always KOd it with +2 Close Combat. I have never tried it on one with full health, though. Interestingly enough, I never run into Skarmory on my best OU team that it would not cause problems for. But on this team that it wreaks havoc on, I now encounter it almost every other battle.
Also worth noting is SkarmBliss. My only one Pokemon that can take it down is Heatran, and only in the order Skarmory-Blissey, and only if Skarmory is dumb enough to stay in against Heatran (surprisingly often).
Very difficult to take down and often phazing. Additionally, I only resist Electric in Rotom.
Powerful confusion-inducing attacker that I cannot hit supereffectively.
This doesn't mean that I'm done changing my team. Because this team still has problems, despite being my best result yet. However, this is only as far as I can get myself. Anyway, let me explain each member's role:
Ninjask @ Leftovers
Adamant
Speed Boost
258 HP / 8 Atk / 184 Def / 68 Spe
-Protect
-X-Scissor
-Substitute
-Baton Pass
X-Scissor gets some extremely useful quick KO's, and even some full HP 2HKOs, like on Roserade. I know some people that don't use an attack move on Ninjask, but that just doesn't work. One advantage this Ninjask has over the Swords Dance variant is Protect, which I am not sure how the Swords Dance Ninjask can survive without it. It lets Ninjask live longer via Leftovers, and prevents TrickScarf leads from working, Jirachi in particular. This Ninjask is bulky enough to survive mocst priority attacks and come back in later for more speed passing.
Synergy:
ExtremeSpeed - Aggron, Heatran, Rotom
Bullet Punch - Heatran, Starmie, Rotom
Ice Shard - Aggron, Heatran, Starmie
Mach Punch, Vacuum Wave: Heracross, Starmie, Rotom
Heracross @ Wide Lens
Adamant
Guts
252 Atk / 252 Spe / 4 SpD
-Swords Dance
-Megahorn
-Close Combat
-Night Slash
The first of my speed-receiving sweepers. Wide Lens is the only way I can use Megahorn, because I have absolutely terrible luck with accuracy. For instance, I once missed twice in a row with a Lens-boosted Aqua Tail, at 99 accuracy, not even against Gliscor in Sandstorm or Froslass in Hail. I chose Night Slash over Stone Edge to deal with Ghosts that resist both Megahorn and Close Combat. It is more useful overall, but leaves me useless against Zapdos (and obviously Gliscor, the Heracross counter).
Synergy:
Fire - Heatran, Starmie
Psychic - Aggron, Heatran, Starmie
Flying - Aggron, Heatran, Rotom
Aggron @ Wide Lens
Adamant
Rock Head
4 HP / 252 Atk / 252 Spe
-Head Smash
-Earthquake
-Aqua Tail
-Magnet Rise
252 Speed EVs is to not leave me completely useless without a Speed boost. Once again, Wide Lens is the only way I can use this set. Once, I got the Wide Lens Tricked away, and I missed with Head Smash right away and lost the battle. Originally I had Tyranitar here, but only because Head Smash wasn't appearing on Aggron's move list. Sandstorn was bad for my Ninjask, however, so I found a way to get Head Smash back using the online team builder. Aqua Tail is strictly for when rock is not very effective AND water is supereffective - even resisted Head Smash is more powerful. Earthquake seems surprisingly weak, but then again I usually use it either with STAB or a more powerful Pokemon. I only use Magnet Rise when I predict a Ground attack, because he is fast enough to pull it off and dodge the attack after a speed increase.
Synergy:
Ground - Ninjask, Heracross, Rotom and Magnet Rise
Fighting - Ninjask, Heracross, Starmie, Rotom
Water - Starmie
Heatran @ Life Orb
Rash (+SpA, -SpD)
Flash Fire
4 Atk / 252 SpA / 252 Spe
-Flamethrower
-Earth Power
-Hidden Power Grass
-Explosion
Scarf without Choice. When Ninjask is getting attacked by a Fire attack, I can pass 3 or 4 speed boosts and get a Flash Fire boost. This sweep is potentially game-ending. If not, it is definitely game-changing. When Blissey gets in my way, Explosion KOs. I hate having to resort to this, but it is worth it to get rid of her. Occasionally I will Explode on Dragonite, Salamence and Flygon, because they resist my attacks and I cannot allow them to sweep. Other than Dragonite and Salamence, I cannot think of anyone off the top of my head who resists Fire+Ground+Grass.
Synergy:
Ground - Ninjask, Heracross, Rotom
Fighting - Ninjask, Heracross, Starmie, Rotom
Water - Starmie
Starmie @ Leftovers
Timid
Natural Cure
136 HP / 156 Def / 216 Spe
-Rapid Spin
-Thunderbolt
-Surf
-Recover
I don't really like Starmie, but I couldn't think of a better choice for Rapid Spin support. In trying to keep my Ninjask alive, I had to choose between Wish and Rapid Spin support, as there are no Pokemon who learn both. I've tried using both Wish and Rapid Spin, but there is no room for two support Pokemon, and I've tried using just Wish, but Ninjask was harder to keep alive without Rapid Spin. So I settled with just Rapid Spin, but lack of Wish is pretty harsh.
Unless they're accompanied by Stealth Rock or Spikes, I won't spin Toxic Spikes - the only member they hurt is this Starmie (whom it would be too late to Spin because he is already poisoned), and they are arguably beneficial for Heracross, making it a short-lived but extremely powerful sweeper.
Synergy:
Dark - Heracross, Aggron, Heatran
Ghost - Aggron, Heatran
Bug - Heracross, Aggron, Heatran, Rotom
Grass - Ninjask, Heracross, Heatran
Electric - Rotom (slightly problematic)
Rotom-C @ Life Orb
Modest
Levitate
6 HP / 252 SpA / 252 Spe
-Thunderbolt
-Shadow Ball
-Leaf Storm
-Hidden Power Ice
What I needed for my final sweeper was immunity to Aggron's (and Heatran's) huge Ground and Fighting weakness, and someone who resists Electric attacks, which I lack elsewhere. Rotom-A fit this role perfectly, of course. I didn't spend too much time on deciding which forme to use; and to be honest, I am not sure if this one is the best choice. Leaf Storm is powerful and occasionally very useful, but I have to switch afterward, losing my speed boosts. I am considering switching to the Fan forme, which I use in my most powerful OU team and it works very well. That would give me an answer to Machamp, and Breloom (I would probably need Chesto Berry for this). HP Ice is my only Ice attack unfortunately, and is strictly for the 4x weak Gliscor, Dragonite, Salamence, and Flygon.
Synergy:
Dark - Heracross, Aggron, Heatran
Ghost - Aggron, Heatran
Threats:
Certain variants of pretty much anything can cause problems for this team. But these threats are ones that I noticed were recurring and could always cause trouble:
Despite being destroyed by two members of my team, Skarmory causes problems with Whirlwind, obviously. Even if I get Heatran or Rotom in, Skarmory will just switch out and come back later for more phazing. Skarmory also OHKOs my Heracross with Brave Bird, but I have always KOd it with +2 Close Combat. I have never tried it on one with full health, though. Interestingly enough, I never run into Skarmory on my best OU team that it would not cause problems for. But on this team that it wreaks havoc on, I now encounter it almost every other battle.
Also worth noting is SkarmBliss. My only one Pokemon that can take it down is Heatran, and only in the order Skarmory-Blissey, and only if Skarmory is dumb enough to stay in against Heatran (surprisingly often).
Very difficult to take down and often phazing. Additionally, I only resist Electric in Rotom.
Powerful confusion-inducing attacker that I cannot hit supereffectively.
