Ok your team is in need of some major changes. I will keep most of your team, but I will replace their sets.
First Beedrill...
Beedrill is an awesome physical sweeper (IMO), but the set is all over the place. Roost is not worth it as Beedrill can be one shotted pretty easily. Here is a better set.
Beedrill-Mega @ Beedrillite
Ability: Adaptability
EVs: 252 Atk / 252 Spe
Jolly Nature
- U -turn
- Poison Jab
- Drill Run/Knock Off
- Protect
Your nature didn't benefit Beedrill at all. Protect is used to let Beedril mega safely and gain its speed next turn. Drill Run can be replaced by Knock Off to cover ghosts and add some utility, but its up to you.
Excadrill @ Choice Scarf
Ability: Mold Breaker
EVs: 252 Atk / 252 Spe
Jolly Nature
- Earthquake
- Rock Slide
- Iron Head
- Rapid Spin
Even though this set is often used (and I hate over used sets), it is very effective. Choice Scarf will make you peak at a 453 speed stat. Earthquake can hit annoying Rotom forms (except Rotom - Fan). Rock Slide is used for Flying types, Iron Head a fairy killer and Rapid Spin for utility.
(I removed Lucario as you already have a Steel type and need a wall)
Slowbro @ Leftovers
Ability: Regenerator
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
- Slack Off
- Psyshock
- Scald
- Calm Mind
Since the meta nowadays is mainly physical, I have decided to put Slowbro. It can tank any unboosted physical hit. Bold nature ensures no physical threats can break through Slowbro. Calm Mind boosts your hindering SpD stat and boosts Slowbro's SpA. Scald is standard and Psyshock is used over Psychic to check SpD walls such as Chansey or Blissey.
Gengar @ Focus Sash
Ability: Levitate
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Taunt
- Destiny Bond
- Shadow Ball
- Sludge Bomb
Here is the set I use on my Gengar. you usually lead off with taunt if you feel a set up. Shadow Ball and Sludge Bomb are used to wreak havoc. If you can bait the opponent into a Destiny Bond after the Sash is consumed, you can take out a key part of their team. The only pokemon that really walls this set is Ferrothorn, who usually switches out after a taunt.
Even though I said you already have a steel type, Klefki can really mess with the opponent.
Klefki @ Air Balloon
Ability: Prankster
EVs: 252 HP / 252 Def / 4 SpD
Careful Nature
- Foul Play
- Thunder Wave
- Light Screen
- Spikes
Air Ballon is used so Klefki effectively has only one weakness. Thunder Wave can slow down fast threats and Light Screen provides some protection against SpA sweepers. Foul Play and spikes are standard
Talonflame @ Sitrus Berry
Ability: Gale Wings
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
- Swords Dance
- Flare Blitz
- Brave Bird
- Roost
Even though this set is overused, it is effective. Get rid of Flamethrower for Flare Blitz.
There we have it! I hope I helped!
