Gourgeist help

[Akiko15]

Okay so I'm making a Mono-team(ghost) and I admit that I only got into competitive play a few months ago. This Gourgeist I'm working on is giving me a little troubles with it's ability since I don't know whether to go with Frisk or Insomnia. It's pretty much a Staller, Impish nature, the moves are: Trick-or-treat, Toxic, Phantom Force, and Leech Seed. I have no idea what to make the item, either. Maybe a Lum Berry. But either way, I really need some outside input on whether I should go with Frisk or Insomnia.

[Black117]

First off what format you are using this particular gourgeist build. Honestly if its either singles or doubles, frisk might be the better ability since gourgeist being a grass type pokemon is immune to two of the most common sleep moves in the game: spore and sleep powder. That leaves dark void, lovely kiss, sing, hypnosis, and yawn which a good majority are inaccurate. Frisk reveals the items of every enemy pokemon on the field so you can easily predict what particular set a certain pokemon run.I can help on certain occasions to determine what particular pokemon build the opponent s running. I know you didn't ask for moveset I would change trick-or-treat for seed bomb or protect since people can easily get rid of the condition by switching out.

[Akiko15]

The team itself would probably be good in Singles or Doubles, I think. Maybe more of singles.
I was leaning more towards Frisk, and now I'm sure that it would be best to go with that, thank you.
Hmm...I'll think a little more on the moveset, thanks for the advice :3

[Marcusube]

I have a singles build for Gourgeist. I also think that Frisk is better for Gourgeist than Insomnia, seeing as how the most common move to put Pokemon to sleep is of grass typing which Gourgeist is immune to and anything that can put it to sleep would be able to faint it before Gourgeist gets set up. So my idea is:

Gourgeist-Super @ Leftovers
Ability: Frisk
Level: 50
EVs: 252 HP / 220 Def / 36 SpD
Impish Nature
- Trick-or-Treat
- Will-O-Wisp
- Shadow Sneak/Phantom Force
- Leech Seed

Defensive Calculations

252+ Atk Choice Band Talonflame Brave Bird vs. 252 HP / 220+ Def Gourgeist-Super: 158-188 (82.2 - 97.9%) -- guaranteed 2HKO

I am under the assumption that you are either using an average sized Gourgeist or the event Super Gourgeist for no other size gets Insomnia.

I threw out Toxic for Will-o-Wisp mainly because Toxic doesn't affect steel types or poison types. Will-o-Wisp affects all typing except fire but it also cuts the opponents attack stat in half which makes Gourgeist last longer as a physical wall. Trick-or-Treat is a nice touch I must admit. I hope you will consider combining it with Sucker Punch in doubles kappa . Shadow Sneak is to get even more chip damage off when stalling out the opponent + it has priority, however, Phantom Force gives you a turn of invulnerability and deals 90 base damage plus STAB. Leech Seed is good for it scares the opponent out into another Pokemon, and with the correct predictions, you can get a perfect switch in and turn the game to your favor in singles.

Try it and I hope it works for you