https://www.smogon.com/dex/rs/pokemon/ariados/
[Overview]
Baton Pass is a very strong archetype in ADV and this holds true all the way down in NU. While Ariados itself is nothing to write home about, its unique ability to Baton Pass a trapping move gives it a secure place on every Baton Pass chain. While Ariados's overall stats and movepool are lackluster, it does sport decent Attack, can pass Agility, and is practically immune to Hitmonchan's STAB moves, meaning it does have some utility on the chain outside of Spider Web. Ultimately, however, if you're not using Ariados to Baton Pass, you're doing it wrong.
[SET]
name: TrapPass
move 1: Spider Web
move 2: Agility
move 3: Baton Pass
move 4: Substitute / Signal Beam
item: Leftovers
ability: Insomnia
nature: Jolly
evs: 252 HP / 4 Atk / 252 Spe
[SET COMMENTS]
- Typically you'll want to have Defense or Special Defense boosts before bringing in Ariados in order to give it time to set up Agility and choose the opponent's victim with Spider Web
- If not possible, get it in on a Choice-locked Fighting-type move or something with low attacking power like Sableye
- Last slot depends more on if you're using Ariados on a full BP chain or more of a short pass team. Substitute if full BP in order to as safely continue the chain as possible. Signal Beam prevents Ariados from becoming dead in the water and can even let Ariados feasibly sweep if passed Attack and Defense boosts.
[ADDITIONAL SET COMMENTS]
- Sludge Bomb can be used over Signal Beam as it's stronger and can prevent Tropius from using Whirlwind, but will leave it exposed to more Pokemon like Mawile
- Some Speed can be dropped to just outspeed Raticate after an Agility, but max Speed lets Ariados outrun +1 Kingler
- Typical full BP chain teammates needed, Huntail, Volbeat, Mawile
[Other Options]
- Night Shade
- Refresh
- Choice Band
[Checks and Counters]
- Roar Wailord, Whirlwind Tropius, Roar Flareon
- Explosion Graveler, Metang, Sudowoodo
- Taunt Mawile
- Chimecho and Haunter
- Shedinja