Question

Mine knows:

Bug Buzz: Good power, high accuracy, chance to lower Sp. Def, STAB, used to deal with Psychic types.

Toxic: Inflicts toxic poison.

Light Screen: Increases Sp. Def.

Psychic: Good power, high accuracy, chance to lower Sp. Def.

Dustox learnset

Comments

Dustox (M) @ Focus Sash
Trait: Shield Dust
EVs: 252 SAtk / 4 SDef / 252 Spd
Modest Nature (+SAtk, -Atk)
- Butterfly Dance
- Sludge Bomb
- Bug Buzz
- Hidden Power [Electric]

Answer 1

Replace Light Screen with Reflect as Dustox already has high special defense. Energy Ball might be a good replacment if you don't want reflect.

Answer 2

Dustox @ Heat Rock/Lefties

Trait: Shield Dust

EVs: 248 HP / 8 Def / 252 SpA

Modest Nature (+SpA, -Atk)

• Sunny Day
• SolarBeam
• Hidden Power Fire
• Moonlight

Sunny Day support.
SolarBeam is good accuracy and power and can be used thanks to Sunny Day.
Hidden Power Fire is boosted by the sun and hits grass types.
Moonlight is for healing and heals extra in Sun.

Answer 3

Maybe energy ball instead of psychic to deal with rock weakness.

Answer 4

Gen V

Dustox (M) @ Focus Sash
Trait: Shield Dust
EVs: 252 SAtk / 4 SDef / 252 Spd
Modest Nature (+SAtk, -Atk)
- Giga Drain
- Sludge Bomb
- Quiver Dance
- Bug Buzz