I haven't used mono ghost since the Crown Tundra was released so sorry if these suggestions are bad.
Gengar
Why Focus Punch? Gengar has a pitiful base 65 attack, so even if you correcty predict a switch you won't be hitting hard. Swap it for Shadow Ball, it comes off of Gengar's much higher base special attack and gets STAB. Since you'll have no physical attacks put the 4 attack EVs into defence instead and use a Timid nature. I also suggest Sludge Wave over Thunderbolt, but you can keep Thunderbolt if you want, as it hits water types such as Toxapex super-effectively, or swap Destiny Bond for Sludge Wave and use a Choice Scarf as the item. Dazzling Gleam is also an option for hitting Dark Types instead of the famously unreliable Focus Miss Focus Blast.
Updated set:
Gengar @ Focus Sash / Choice Scarf
Ability: Cursed Body
Shiny: Yes
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Destiny Bond / Sludge Wave
- Focus Blast / Dazzling Gleam
- Thunderbolt / Sludge Wave
- Shadow Ball
Mimikyu
Remember when you posted a Mimikyu set on the Rate My Pokemon thread and I responded with improvements? The EVs and nature are still different from what I suggested, but the moveset itself is fine. Just go with an EV spread of 252 Atk / 4 Def / 252 Spe with a Jolly nature. Drain Punch can be used over Shadow Claw to hit Dark types super-effectively, or Wood Hammer to hit water types.
Updated set:
Mimikyu (M) @ Life Orb
Ability: Disguise
Shiny: Yes
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Play Rough
- Swords Dance
- Shadow Sneak
- Drain Punch / Shadow Claw / Wood Hammer
Froslass
Holy **** that set is evil. You could add Hail onto the set in place of Ice Beam to be even more annoying. As much as I like it, I don't recommend it. Its quite dependent on luck though, and it takes multiple turns to set up, and you should have 252 EVs in HP and speed so you can use Thunder Wave or Attract before they can hit you. Not to mention that Froslass is pretty frail. However, Froslass should normally be used as a suicide lead to set up Spikes and take out an opponent with Destiny Bond. If you want to troll people you could use your original set but I'll still make an updated set for it.
Updated sets:
Troll (NOT RECOMMENDED)
Froslass @ Bright Powder
Ability: Snow Cloak
Shiny: Yes
EVs: 252 HP / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Hex
- Thunder Wave
- Attract
- Hail
Lead (recommended)
Froslass @ Focus Sash
Ability: Cursed Body
Shiny: Yes
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Spikes
- Destiny Bond
- Shadow Ball / Taunt
- Ice Beam
Aegislash
If you're running Swords Dance, why a Timid nature? It lowers your most prominent stat. You should run an Adamant nature instead because Aegislash isn't very fast. Swap Shadow Ball for Iron Head, as that gets STAB, and run Close Combat over Sacred Sword for the extra power. You could also swap the Weakness Policy for a Life Orb. Also, this is just me but I really like mixed Weakness Policy Aegislash with King's Shield, Flash Cannon, Shadow Ball and Shadow Sneak, so I'll leave that below as well if you want to use it.
Updated sets:
Swords Dance
Aegislash @ Life Orb
Ability: Stance Change
Shiny: Yes
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Swords Dance
- Iron Head
- Shadow Sneak
- Close Combat
Mixed
Aegislash @ Weakness Policy
Ability: Stance Change
Shiny: Yes
EVs: 252 HP / 4 SpA / 252 SpD
Sassy nature
- King's Shield
- Shadow Ball
- Shadow Sneak
- Flash Cannon
Spiritomb
I don't really know what to say about this (apart from "why are you running speed EVs and a Naive nature on a Pokémon with base 35 speed?"), because I stopped using mono ghost before Spiritomb was released. Sableye is the better Dark/Ghost thanks to Prankster, but you could use Galarian Corsola as a defensive Pokémon instead. Here are sets for both:
Sableye
Sableye @ Leftovers
Ability: Prankster
Shiny: Yes
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Will-O-Wisp
- Taunt
- Recover
- Knock Off
Galarian Corsola
Corsola-Galar @ Eviolite
Ability: Cursed Body
Shiny: Yes
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
IVs: 0 Atk
- Night Shade
- Will-O-Wisp
- Strength Sap
- Haze
Polteageist
Polteageist has the same base attack stat as Gengar, so it shouldn't be running Poltergeist, even with the Shell Smash boost. Swap it for Stored Power. Stored Power has an insane base power of 140 after you use Shell Smash, and gains an extra 40 base power if Weak Armor activates. Also, you shouldn't run an EV spread of 252 Atk / 252 SpA, so change it to 4 Def / 252 SpA / 252 Spe with a Modest nature.
Updated set:
Polteageist @ Focus Sash
Ability: Weak Armor
Shiny: Yes
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
- Shell Smash
- Shadow Ball
- Giga Drain
- Stored Power
Hope this helps!
