Gen 8 Doubles OU
Rillaboom @ Assault Vest
Ability: Grassy Surge
EVs: 248 HP / 120 Atk / 36 Def / 100 SpD / 4 Spe
Adamant Nature
- Fake Out
- Grassy Glide
- High Horsepower / Superpower
- U-turn
Pretty similar to the sample set on Smogon, but with a few changes.
Fake Out flinches an opponent, preventing them from moving and allowing Rillaboom's ally to attack or set up something like Tailwind more safely. Grassy Glide is pretty much mandatory on Rillaboom. It's STAB that, in the Grassy terrain provided by Grassy Surge, has priority. High Horsepower and Superpower are options for hitting steel types super effectively, but I only recommend using High Horsepower if you have a Tailwind setter on your team. High Horsepower OHKOs fast Heatran (Tailwind support is needed to outspeed it), while Superpower hits Kartana hard. U-Turn is for pivoting.
The EVs are mostly the same as those on Smogon's sample set, but I did make one change; I moved 4 of the attack EVs into speed, meaning this Rillaboom can always Fake Out opposing 0 speed Rillaboom before they can use their own Fake Out. The rest of the EVs allow Rillaboom to survive either a +1 U-Turn from Genesect or a +1 Sludge Bomb from Nihilego (thanks to the Assault Vest).