TrollFreak is helping me write this one.
First analysis too, having a lot of fun making this.
Torterra
[Overview]
<p>Torterra faces stiff competition from other, bulkier Grass-types in the VGC 2012 metagame, such as Ferrothorn. However, with a respectable base 109 Attack, decent stats around the board, an immunity to Discharge, one of the most common spread moves in the metagame, along with the growing popularity of Pokemon it can handle such as Gastrodon and Swampert, this turtle can really make the earth shake.</p>
[SET]
name: Trick Room Attacker
move 1: Wood Hammer / Seed Bomb
move 2: Earthquake
move 3: Rock Slide
move 4: Protect / Wide Guard
item: Life Orb / Focus Sash
ability: Overgrow
nature: Brave
evs: 252 HP / 252 Atk / 4 Def
ivs: 0 Spe
[SET COMMENTS]
<p>This set is meant to fully utilize one of Torterra’s best perks: its base 109 Attack stat. The hardest decision when using Torterra is whether to run Wood Hammer or Seed Bomb. Wood Hammer is the more powerful option, but its recoil forces the use of a Life Orb, as it is illogical with a Focus Sash. However, if you don't want to suffer from any of these downsides and still want to use Focus Sash, Seed Bomb is your best option. Earthquake is a given move, serving as a powerful STAB attack. Rock Slide is also mandatory, hitting the Flying-types that resist Torterra's STABs. Protect is also needed, as nearly every other VGC Pokemon uses it too, and it also can be used to scout attacks. Wide Guard can be considered because it blocks Heat Wave and Blizzard, two common moves in the metagame. A Brave Nature plus 0 Speed IVs are needed to minimize Speed while maximizing Attack, which furthers Torterra's excellence as a Trick Room sweeper.</p>
[ADDITIONAL COMMENTS]
<p>To fully utilize this set, Trick Room is an absolute must. Cresselia, Musharna, and Bronzong act as amazing partners, with immunity to Earthquake and, in Cresselia and Musharna's case, the ability to boost the power of Earthquake with Helping Hand. Other good partners are other Trick Room users, such as Dusclops, Reuniclus, Slowking, among many others; however, they lack said Earthquake immunity. Pokemon that can set up weather, such as Tyranitar and Hippowdon, also pair greatly with Torterra. Tyranitar is the highest recommended, seeing as they are both immune to Sandstorm recoil and their only common weakness is Bug, which is almost never seen in the VGC metagame. It is also worth mentioning again that Torterra can be a great Swampert, Gastrodon, and Rhyperior counter. Another effective combo is Torterra in conjunction with the Rotom formes, as they can eliminate Torterra's threats, such as Tornadus, Thundurus, Scizor, and Fire-types, depending on the form. To add to the success of their pairing, Rotom is immune to the turtle's Earthquakes, and Torterra is immune to Discharge as well.</p>
[Other Options]
<p>Crunch is a viable option, allowing you to deal a little bit better with Latios, Latias, and other Psychic-types. Yache Berry can also replace Focus Sash or Life Orb, although you lose some of the benefits of the those items. If Life Orb or Focus Sash has already been taken up due to Item Clause, a Grass or Ground Gem is recommended.</p>
[Checks and Counters]
<p>Hail teams are the bane of Torterra's existence, as Blizzard always OHKOes a non-Focus Sash set. Even with Rock Slide, Zapdos, Salamence, and Thundurus still check Torterra effectively, while Ludicolo and Politoed can end him quickly. Teams meant to counter Trick Room will render Torterra useless, as it is very slow.</p>
[Unreleased]
<p>Torterra gets Shell Armor via Dream World, which protects it from critical hits. Although that kind of protection is interesting, critical hits are mostly based on luck anyways, and Shell Armor Torterra is incompatible with Seed Bomb. Overall, Overgrow is the more useful ability, as it can be effectively abused with a Focus Sash.</p>