Well, first thing first is that Misdreavus completely outclasses Duskull.
Misdreavus (M) @ Eviolite
Trait: Levitate
EVs: 36 HP / 40 Def / 160 SAtk / 240 Spd
Timid Nature (+Spd, -Atk)
- Will-O-Wisp / Substitute
- Calm Mind
- Hidden Power [Fighting]
- Shadow Ball
Pawniard is a good Pokemon. However, I would suggest trying out Sandile instead. I think that Ground typing along with no weakness to Ground and Fire will help you out a lot.
Sandile (M) @ Choice Scarf
Trait: Moxie
EVs: 36 HP / 180 Atk / 236 Spd
Jolly Nature (+Spd, -SAtk)
- Foul Play
- Earthquake
- Stone Edge
- Fire Fang
Darumaka and Mienfoo are good.
I know a Shell Smasher is good, but in this case I am thinking you might want to replace it with Staryu, who I think will be a better help to your team.
Staryu @ Eviolite
Trait: Natural Cure
EVs: 36 HP / 196 SAtk / 236 Spd
Timid Nature (+Spd, -Atk)
- Scald
- Thunderbolt
- Rapid Spin
- Ice Beam
Then, I think a Blitzle will serve you better in this case over Joltik.
Blitzle (M) @ Life Orb
Trait: Sap Sipper
EVs: 76 HP / 196 Atk / 228 Spd
Jolly Nature (+Spd, -SAtk)
- Flame Charge
- Quick Attack
- Double Kick
- Wild Charge / Spark
