Chesnaught @ Assault Vest
Ability: Bulletproof
Tera Type: Water
EVs: 180 HP / 76 Atk / 252 SpD
Careful Nature
- Drain Punch
- Earthquake
- Seed Bomb
- Super Fang/Crunch/Stone Edge
Chesnaught could potentially serve a niche role in Gen 9 OU. Its ability, Bulletproof, allows it to switch into common attacks such as Bullet Seed, Energy Ball, Focus Blast, Seed Bomb, Shadow Ball, and Sludge Bomb. Therefore, several Pokemon could potentially be invalidated just by the presence of Chesnaught, such as Amoonguss (without Toxic), Dragapult, Great Tusk, Gholdengo, Hydreigon, Iron Treads, Kingambit, and Meowscarada with proper prediction. 76 Attack EVs allow Chesnaught to 2HKO Clodsire with Earthquake after Leftovers recovery. 180 HP and 252 SpD EVs provide a defensive backbone, allowing Chesnaught to tank numerous special hits such as non-STAB Flamethrowers, Make It Rains, and Draco Meteors. A tera type of Water allows Chesnaught to only take neutral Flying type damage while also allowing it to resist fire attacks and potentially retaliate with super effective Earthquakes. Drain Punch is a STAB recovery option. Earthquake is very strong coverage. Seed Bomb is common grass STAB. Super Fang allows you to chip down opponents such as Corviknight, Amoonguss, and Dondozo easier, but other options such as Crunch can be used for a strong option against Dragapult, or Stone Edge to catch flying types on a switch. While Chesnaught is likely to drop down to a lower tier, it certainly can serve a purpose in OU for the time being.