I built this as a counter to several annoying Pokemon in PU and the team kind of just fell together. It works quite well most of the time, but I wondered if there was a way to make it better. I only use this team on Showdown.
Basculin @ Life Orb
Ability: Mold Breaker
EVs: 252 Atk/252 Spd/4 HP
Nature: Jolly
-Waterfall
-Superpower
-Crunch
-Aqua Jet
Mold Breaker allows it to oneshot Golem and Probopass that want to set stealth rocks with a nice Waterfall or Superpower. Crunch and Aqua Jet are for utility.
Bouffalant @ Assault Vest
Ability: Soundproof
EVs: 252 HP/252 Atk/4 SpDef
Nature: Adamant
-Earthquake
-Megahorn/Payback
-Iron Head
-Return
I got tired of getting swept by Boomburst Chatot, so Soundproof was the way to go. Assault Vest and HP investment lets it survive a lot of hits and hit back like a truck. Iron Head is for 'mons like Articuno and Clefairy. Payback is useful for a super-effective hit against ghost-types or when expecting the opponent to outspeed; Megahorn is good for grass-types like Leafeon and Tangela.
Zebstrika @ Expert Belt
Ability: Lightning Rod
EVs: 252 SpA/252 Spd/4 SpDef
Nature: Modest
-Overheat
-Thunderbolt
-Hidden Power Ice
-Volt Switch
It can soak up electric moves directed at Basculin and then start hurting things. I didn't want to use Life Orb, so I chose Expert Belt for some extra damage on Overheat and HP Ice. Volt Switch is good after dropping on an Overheat.
Kadabra @ Life Orb
Ability: Magic Guard
EVs: 252 SpA/252 Spd/4 SpDef
Nature: Timid
-Psychic
-Dazzling Gleam
-Energy Ball
-Shadow Ball
I needed another special attacker for the team and thought this might work. Due to its frailty, I use it as more of a late-game sweeper than early- or mid-game. Magic Guard + Life Orb = a lot of free damage.
Gourgeist-Small @ Leftovers
Ability: Frisk
EVs: 252 HP/252 SpDef/4 Atk
Nature: Careful
-Will-O-Wisp
-Leech Seed
-Substitute
-Phantom Force
Small form for the best speed stat so as to outspeed as much as possible with a Substitute. SubSeed is very annoying; added Will-O-Wisp and Phantom Force can wreck things that don't have reliable recovery and has caused quite a few ragequits.
Furfrou @ Chesto Berry
Ability: Fur Coat
EVs: 252 HP/252 Spd/4 SpDef
Nature: Timid
-Cotton Guard
-Snarl
-Rest
-Toxic
I love using Furfrou. It's been on every PU team I've ever made. Timid nature allows Furfrou to outspeed Sub Ninetales with a Toxic before it can get set up or get a Cotton Guard up before it gets hit by non-scarf Slaking or Adamant Floatzel. Rest is great for removing Toxic, and Chesto Berry allows Furfrou to execute a quick turn-around into more Cotton Guard or Snarl. Many opponents have forfeited before my Furfrou.