- Boosts power of Water-type moves 50% when at 1/3 HP or less.
Level 100 Statistics (see level 5, 50, 100)
With lackluster stats leaving him seemingly outclassed by other bulky Water-types, you might wonder why anyone would use Blastoise in OU. In particular, Starmie greatly outclasses him as a Rapid Spin user because it can take down Rotom-A; Starmie's higher Speed stat also makes it the more useful Pokemon in general. Furthermore, Blastoise fails to deal heavy damage to both Water- and Grass-types, which lets them easily set up on him. Despite this, Blastoise does have one unique niche: he can function as an effective OU anti-lead.
Blastoise can make an effective OU lead because of his ability to act as a mesh of two other leads; he combines Starmie's spinning capabilities with Empoleon's bulk and access to priority. Hydro Pump hits many leads extremely hard; it is capable of 2HKOing the likes of Metagross, Swampert, Jirachi, and Machamp. Aqua Jet finishes off frail Focus Sash users such as Azelf, Aerodactyl, and Infernape, while Rapid Spin removes Stealth Rock and other entry hazards set up by opposing leads. Ice Beam rounds out the set as a 100% accurate move that can smash through Gliscor and Dragonite leads.
Team Options & Additional Comments >>>
With Choice Specs, Blastoise can make use of his access to Water Spout, which dents anything that doesn't resist it. However, the sheer amount of support required to use it effectively—which comprises of a spinner to remove entry hazards, a Fire-type Pokemon to scare away bulky Grass-types such as Celebi and Shaymin, and a Grass-type Pokemon to force out bulky Water-types, namely Suicune and Vaporeon—makes it an inferior option. Should you choose to use such a set, however, Blastoise should run maximum Speed and a Timid nature to outspeed neutral-natured Lucario, or 208 Speed EVs and a Modest nature to outrun positive-natured Tyranitar.
Blastoise can alternatively attempt a defensive Rapid Spin set. However, unlike Starmie, Blastoise fails to deal heavy damage to the premier spinblocker in the OU metagame: Rotom-A. Foresight enables Blastoise to bypass Rotom-A, but he can only do this once as Rotom-A can 2HKO him with Thunderbolt. Other defensive options include Roar and Yawn, which phaze the opposing Pokemon and remove their boosts, as well as Toxic, which cripples incoming Water-types.
Checks and Counters
Roserade and Celebi can switch into even Life Orb Ice Beam and KO Blastoise with their STAB attacks. Vaporeon, Suicune, and Blissey can all wall Blastoise's attacks and stall him out with Wish, Calm Mind, Toxic, or Seismic Toss respectively. Gyarados and Kingdra can both set up Dragon Dance boosts on Blastoise with near-impunity; the former fears only the rare Hidden Power Electric. Lastly, Rotom-A can switch into Blastoise's attempts at spinning and deal heavy damage with Thunderbolt, but it should be wary of Torrent-boosted Hydro Pump.