I'll list the other common Ghosts in UU
Dusclops @ Eviolite
Ability: Pressure
EVs: 252 HP, 252 Def, 4 Sp. Def
Nature: Bold
- Will-O-Wisp
- Seismic Toss/ Night Shade
- Pain Split/ Rest
- Curse
Sableye @ Leftovers
Ability: Prankster
EVs: 252 HP, 120 Def, 136 Sp. Def
Nature: Calm
- Recover
- Will-O-Wisp
- Taunt
- Foul Play/ Night Shade
Cofagrigus @ Leftvoers
Ability: Mummy
EVs: 248 HP, 252 Def, 8 Sp. Def
Nature: Bold
- WIll-O-Wisp
- Pain Split
- Shadow Ball
- Haze
OR
EVs: 252 HP, 252 Sp. Atk, 4 Def
Nature: Modest
- Shadow Ball
- HP Fighting
- Nasty Plot
- Trick Room
The sign to know if Cofagrigus is offensive or defensive is to see if it sets up Trick Room.
Rotom (normal) @ Choice Scarf/ Specs
Ability: Levitate
EVs: 252 Sp. Atk, 252 Speed, 4 HP
Nature: Modest/ TImid
- Volt Switch
- Shadow Ball
- HP Fighting/ Thunderbolt
- Trick
Rotom can sometimes be running Dual Screens, but it's more common with a Trick set.
I didn't list Spiritomb and Dusknoir because Sableye and Dusclops outclass both of them in their roles in UU.