This is basically one of my first decent teams, but I don't think its quite up to par yet. I've had a fair share of both wins and losses on the OU ladder with this team.
Roserade @ Focus Sash
Ability: Natural Cure
EVs: 4 HP / 252 SpA / 252 Spe
Nature: Timid
- Toxic Spikes
- Sleep Powder
- Leaf Storm
- Hidden Power Fire
Standard toxic spikes Roserade lead. In normal circumstances I would just lay down sleep powder before setting up spikes, but I would switch out against the common Aerodactyl, Jirachi, or basically other pokemon that counter this set. Hidden Power Fire works well against steels (primarily Scizor and Forretress) while Leaf Storm is basically just a normal STAB move on Roserade.
I usually expect my Roserade to die pretty quickly, and basically his role in the team is just to successfully set up toxic spikes and do as much damage as possible before going down.
Blissey @ Leftovers
Ability: Natural Cure
EVs: 24 HP/ 252 Def/ 242 SpD
Nature: Calm
- Aromatheraphy
- Softboiled
- Seismic Toss
- Thunder Wave
The clichéd special wall of this team. I switch in to Blissey upon special sweepers and either aromatheraphy if needed or thunder wave instead. Seismic toss is there for the constant damage and softboiled just makes Blissey harder to kill. One thing I dislike about this set is that this Blissey can’t touch ghost types (Rotom, Gengar mainly) so I’m considering switching Seismic Toss out for Flamethrower or some other move. I also use it in tandem with Gengar to avoid fighting moves.
Slowbro @ Leftovers
Ability: Own Tempo
EVs: 212 HP/ 252 Def/ 44 SpA
Nature: Bold
- Calm Mind
- Slack Off
- Surf
- Ice Beam
My physical wall/calm mind sweeper. I usually open with calm mind if I’m expecting the opponent to switch, then just stack calm minds and slack off when necessary. A straight up surf without any calm mind is rarely used, but sometimes I do that if the opponent is weakened already. Toxic is one of the major weaknesses of the calm mind set, and since my Slowbro doesn’t have rest, it has to rely on Blissey to heal him if needed. Many people don't expect much from Slowbro as it isn't really commonly used. I manage to pull awesome calm mind sweeps from time to time because of this.
Gengar @ Choice Scarf
Ability: Levitate
EVs: 4 Def/ 252 Spe/ 252 SpA
Nature: Timid
- Shadow Ball
- Thunderbolt
- Focus Blast
- Trick
My team’s special sweeper. Its moveset basically gives it good type coverage, and trick is there to hamper pesky dragon dancers/calm minders. Basically I just sweep with whatever appropriate move, and switch to either Swellow or Blissey if I’m expecting a Ghost move. Levitate allows me to block incoming Earthquakes pretty well.
Swellow @ Toxic Orb
Ability: Guts
EVs: 252 Atk/ 252 Spe/ 4 SpD
Nature: Jolly
-Brave Bird
-Facade
-Protect
-U-turn
One of my favourite physical sweepers. I usually scout with protect before sweeping with façade or U-turn straight away if I’m against a rock or steel wall. Brave bird is there for me to hit pesky ghost types. Toxic Orb + Guts + Façade is a really powerful combo that can wreck teams, and Swellow’s relatively high speed also ensures that I can sweep rather efficiently.
Scizor @ Choice Band
Ability: Technician
EVs: 248 HP/ 252 Atk/ 8 Spe
Nature: Adamant
- Bullet Punch
- Superpower
- U-turn
- Pursuit
The other physical sweeper of my team. Bullet punch is very useful against pesky high speed or speed boosted enemies, and superpower gives me coverage against other steel types. U-turn helps me escape from threats and pursuit destroys fleeing enemies. A pretty standard set. Slowbro happens to handle Scizor’s major fire weakness very well.
Basically I think my team is pretty well-balanced as many of my pokemons' weaknesses are covered by one another (Slowbro covers Scizor's fire weakness, Gengar and Blissey/Swellow cover each other), as well as a balanced defense/offense lineup (1 toxic spike user 2 special sweepers, 2 physical sweepers and 1 of each type of wall), but it still lacks some important stuff like a ground attack and rapid spin. I'm thinking of switching Roserade out for a better lead or turning it into a spikes based Roserade. My biggest threat would probably be electric moves since both Slowbro and Swellow are weak to them, and I have no reliable pokemon to absorb electric moves consistently.

Roserade @ Focus Sash
Ability: Natural Cure
EVs: 4 HP / 252 SpA / 252 Spe
Nature: Timid
- Toxic Spikes
- Sleep Powder
- Leaf Storm
- Hidden Power Fire
Standard toxic spikes Roserade lead. In normal circumstances I would just lay down sleep powder before setting up spikes, but I would switch out against the common Aerodactyl, Jirachi, or basically other pokemon that counter this set. Hidden Power Fire works well against steels (primarily Scizor and Forretress) while Leaf Storm is basically just a normal STAB move on Roserade.
I usually expect my Roserade to die pretty quickly, and basically his role in the team is just to successfully set up toxic spikes and do as much damage as possible before going down.

Blissey @ Leftovers
Ability: Natural Cure
EVs: 24 HP/ 252 Def/ 242 SpD
Nature: Calm
- Aromatheraphy
- Softboiled
- Seismic Toss
- Thunder Wave
The clichéd special wall of this team. I switch in to Blissey upon special sweepers and either aromatheraphy if needed or thunder wave instead. Seismic toss is there for the constant damage and softboiled just makes Blissey harder to kill. One thing I dislike about this set is that this Blissey can’t touch ghost types (Rotom, Gengar mainly) so I’m considering switching Seismic Toss out for Flamethrower or some other move. I also use it in tandem with Gengar to avoid fighting moves.

Slowbro @ Leftovers
Ability: Own Tempo
EVs: 212 HP/ 252 Def/ 44 SpA
Nature: Bold
- Calm Mind
- Slack Off
- Surf
- Ice Beam
My physical wall/calm mind sweeper. I usually open with calm mind if I’m expecting the opponent to switch, then just stack calm minds and slack off when necessary. A straight up surf without any calm mind is rarely used, but sometimes I do that if the opponent is weakened already. Toxic is one of the major weaknesses of the calm mind set, and since my Slowbro doesn’t have rest, it has to rely on Blissey to heal him if needed. Many people don't expect much from Slowbro as it isn't really commonly used. I manage to pull awesome calm mind sweeps from time to time because of this.

Gengar @ Choice Scarf
Ability: Levitate
EVs: 4 Def/ 252 Spe/ 252 SpA
Nature: Timid
- Shadow Ball
- Thunderbolt
- Focus Blast
- Trick
My team’s special sweeper. Its moveset basically gives it good type coverage, and trick is there to hamper pesky dragon dancers/calm minders. Basically I just sweep with whatever appropriate move, and switch to either Swellow or Blissey if I’m expecting a Ghost move. Levitate allows me to block incoming Earthquakes pretty well.

Swellow @ Toxic Orb
Ability: Guts
EVs: 252 Atk/ 252 Spe/ 4 SpD
Nature: Jolly
-Brave Bird
-Facade
-Protect
-U-turn
One of my favourite physical sweepers. I usually scout with protect before sweeping with façade or U-turn straight away if I’m against a rock or steel wall. Brave bird is there for me to hit pesky ghost types. Toxic Orb + Guts + Façade is a really powerful combo that can wreck teams, and Swellow’s relatively high speed also ensures that I can sweep rather efficiently.

Scizor @ Choice Band
Ability: Technician
EVs: 248 HP/ 252 Atk/ 8 Spe
Nature: Adamant
- Bullet Punch
- Superpower
- U-turn
- Pursuit
The other physical sweeper of my team. Bullet punch is very useful against pesky high speed or speed boosted enemies, and superpower gives me coverage against other steel types. U-turn helps me escape from threats and pursuit destroys fleeing enemies. A pretty standard set. Slowbro happens to handle Scizor’s major fire weakness very well.
Basically I think my team is pretty well-balanced as many of my pokemons' weaknesses are covered by one another (Slowbro covers Scizor's fire weakness, Gengar and Blissey/Swellow cover each other), as well as a balanced defense/offense lineup (1 toxic spike user 2 special sweepers, 2 physical sweepers and 1 of each type of wall), but it still lacks some important stuff like a ground attack and rapid spin. I'm thinking of switching Roserade out for a better lead or turning it into a spikes based Roserade. My biggest threat would probably be electric moves since both Slowbro and Swellow are weak to them, and I have no reliable pokemon to absorb electric moves consistently.