Question

Ghostie =3 (Sableye) (M) @ Leftovers

Trait: Prankster
EVs: 252 HP / 252 Def / 4 SDef
Bold Nature (+Def, -Atk)
- Taunt
- Calm Mind
- Shadow Ball
- Recover

I'ma screwya (Banette) (M) @ Focus Sash

Trait: Cursed Body
EVs: 252 HP / 252 Atk / 4 Def
Brave Nature (+Atk, -Spd)
- Shadow Claw
- Trick Room
- Destiny Bond
- Frustration

Like a Boss (Golurk) @ Life Orb

Trait: No Guard
EVs: 252 HP / 252 Atk / 4 Def
Lonely Nature (+Atk, -Def)
- Earthquake
- DynamicPunch
- Shadow Punch
- Stone Edge

O+++O (Chandelure) (M) @ Leftovers

Trait: Flash Fire
EVs: 252 HP / 4 Def / 252 SAtk
Quiet Nature (+SAtk, -Spd)
- Trick Room
- Flamethrower
- Energy Ball
- Shadow Ball

Kingru (Dusknoir) (M) @ Life Orb

Trait: Pressure
EVs: 252 HP / 252 Atk / 4 Def
Brave Nature (+Atk, -Spd)
- Trick Room
- Shadow Punch
- ThunderPunch
- Ice Punch

Too Alive (Gengar) (M) @ Choice Specs

Trait: Levitate
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Shadow Ball
- Focus Blast
- Thunderbolt
- Sludge Bomb

Answer 1

I'll give this a shot.

Sableye

Consider Hidden Power Fighting, but giving up Taunt might not be worth it.
Though normal types should be removed before Sableye tries to sweep if you don't run Hidden Power Fighting.

Banette

Make the Ghost happy and give it Return? I like to run my pokes max happiness either way.
Also, Focus Sash and 252 HP EVs doesn't really make sence, you want to be sure Destiny Bond takes down the foe it's used on.
Therefore, change IVs to 0 HP / 0 Def / 0 SpD and keep Attack EVs only.
Taunt can also be moved from Sableye to Banette over Frustration/Return.

Golurk

I'm assuming this is just a mistake, but Lonely is useless here.
Change to Brave because this is a Trick Room team.

Chandelure

Though missing Fire Blast pisses me off, that's what I like to run to roast things harder.
Looks good otherwise.

Dusknoir

My suggestions is run Brick Break over Thunderpunch to have an easier time dealing with those pesky normal types, and for the perfect neutral coverage Ghost/Fighting offers.

Gengar

This looks good.
If you want, you can try Gengar's deadly SubDisable set, but Thunderbolt might be crucial to deal with Gyarados.