What is a good moveset for Thievul?

Question

If you have a good competitive moveset for Thievul, post an answer below and upvote the best ones. Movesets for any of its pre-evolutions can also be shared on this thread.

Be sure to include full set details in your post, e.g. items, abilities, natures and EVs. Some explanation, including the intended game mode for your set, is also appreciated. Access the full list of guidelines here.

Thievul Pokedex and learnset for reference.

Answer 1

Thievul @ Choice Specs
Ability: Stakeout (when it's available, otherwise any other ability is fine)
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Dark Pulse
- Psychic
- Grass Knot
- Parting Shot / U-turn

Stakeout is Thievul's best ability. Dark Pulse is STAB, Psychic is Fighting coverage, and the rest of the moveset is coverage against other things.

Comments

I'd highly suggest you replace Shadow Ball with Parting Shot or U-turn, as Dark Pulse covers the same things Shadow Ball does but gets STAB, and the ability to pivot on a Choice user is an important asset.

Answer 2

Thievul @ Psychic Seed
Ability: Unburden
EVs: 252 SpA / 4 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Dark Pulse
- Psychic
- Grass Knot
- Nasty Plot

To be used in Psychic Terrain so Psychic Seed can activate, doubling Thievul's speed thanks to Unburden. Psychic Terrain also helps with Thievul not getting revenge killed by most Pokémon. Dark Pulse is STAB. Psychic and Grass Knot are for coverage. Nasty Plot boosts your Special Attack.

Answer 3

Thievul @ Focus Sash
Ability: Unburden
EVs: 4 Atk, 252 SpAtk, 252 Spe
Nature: Rash
IVs: 0 HP, 0 Def, 0 SpDef
- Dark Pulse
- Psychic
- Grass Knot
- Nasty Plot

The goal of this Set is to get one-shotted so your Sash will activate, giving you a Speed boost, which is why you want the frailest Thievul possible. Then attempt to sweep with Thievul's trash coverage.

Answer 4

Thievul @ Choice Band
Ability: Stakeout
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
- Assurance
- Ice Fang
- Play Rough
- Thunder Fang
With Stealth Rock and/or Toxic Spikes, Assurance is absurdly powerful - about 540 BP, I believe.