I threw together an idea for your mono-type team and this is what I have.
Toxicroak @ Life Orb
Ability: Anticipation
Level: 50
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Fake Out
- Sucker Punch
- Gunk Shot
- Protect
Fake Out is a very good move in VGC as it has a +3 priority and 100% chance to flinch the opponent which means that only one Pokemon on the opponents team will move the first turn. Sucker Punch for priority, Gunk Shot for STAB and a super effective hit against Grass and Fairy types and Protect is just good for....protecting.
Crobat @ Black Sludge
Ability: Inner Focus
Level: 50
EVs: 248 HP / 40 Atk / 220 Spe
Jolly Nature
- Tailwind
- Brave Bird
- Quick Guard
- U-turn
Inner Focus prevents Fake Out from stopping this set up. The idea is Tailwind on the first turn then sweep. Brave Bird is for offense, Quick Guard - to protect your team from priority moves and U-Turn to get damage in and a switch on the same turn.
Drapion @ Leftovers
Ability: Battle Armor
Level: 50
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Earthquake
- Ice Fang
- Protect
- Knock Off
Earthquake hits everything on the field, Ice Fang for Dragon type pokemon and Knock off is to remove held items and also for a STAB offensive move and Battle Armor just keeps your Drapion from taking critical hits.
Venusaur-Mega @ Venusaurite
Ability: Thick Fat
Level: 50
EVs: 252 HP / 252 Def / 4 SpA
Modest Nature
- Sleep Powder
- Sludge Bomb
- Protect
- Giga Drain
Sleep Powder is to stop the opponent from attacking for 1-3 turns, Sludge Bomb for offense and Giga Drain for sustain.
What do you think?