http://veekun.com/dex/pokemon/cloyster
QC Approved: Fireburn, Theorymon
GP Approved: cosmicexplorer, zdrup15 (post-check changes approved by Fatecrashers)
[Overview]
<p>Although mostly outclassed as a supporter by Ferrothorn and Forretress, Cloyster makes for a surprisingly deadly sweeper in Ubers. Its horrendous Special Defense makes it difficult to set up, but when it does get that Shell Smash off there is very little that can stop it. Cloyster requires a lot of team support to work effectively, but when it has it Cloyster is a fearsome sweeper.</p>
[SET]
name: Uber Shell Smash
move 1: Shell Smash
move 2: Icicle Spear
move 3: Hydro Pump
move 4: Rock Blast
item: Life Orb
ability: Skill Link
nature: Naive
evs: 232 Atk / 32 SpA / 244 Spe
[SET COMMENTS]
<p>Cloyster becomes incredibly difficult to wall after a Shell Smash, since it is capable of OHKOing many premier Ubers walls, such as Groudon, Lugia, and Giratina, thanks to its powerful Ice-type STAB. Icicle Spear is the crux of the set, because with Skill Link it effectively has a Base Power of 125. With rain support from Kyogre, a +2 Hydro Pump can KO many Steel-types who would normally wall Cloyster. Rock Blast obtains an immediate OHKO on Ho-Oh, and is Cloyster's strongest attack against opposing Kyogre.</p>
[ADDITIONAL COMMENTS]
<p>Life Orb is absolutely crucial due to the power it provides. A Naive nature with the given Speed EVs guarantees that Cloyster outspeeds Jolly Choice Scarf Terrakion after a Shell Smash. 32 SpA EVs guarantee that a +2 Hydro Pump in the rain will OHKO Steel Arceus after one layer of Spikes. The rest of the EVs are dumped into Attack.</p>
<p>The following damage calculations give an idea of the raw power Cloyster wields after a Shell Smash:</p>
<ul class="damage_calculation">
<li>+2 Icicle Spear vs. 252/252 Impish Groudon: 121.5% - 143.5%</li>
<li>+2 Icicle Spear vs. 252/252 Impish Giratina: 109% - 131%</li>
<li>+2 Icicle Spear vs. 4/0 Palkia: 130.5% - 155.5%</li>
<li>+2 Icicle Spear vs. 4/0 Dialga: 105.5% - 125.5%</li>
<li>+2 Icicle Spear vs. 252/4 Dialga: 89% - 106.5%</li>
<li>+2 Icicle Spear vs. 252/4 Ferrothorn: 95% - 112%</li>
<li>+2 Icicle Spear vs. 252/176 Impish Lugia: 125% - 151.5%</li>
<li>+2 Icicle Spear vs. 252/252 Bold Arceus: 62% - 74.5%</li>
<li>+0 Icicle Spear vs. 0/0 Giratina-O: 97.5% - 118%</li>
<li>+2 Hydro Pump in Rain vs 248/0 Steel Arceus: 88% - 103.6%</li>
<li>+2 Rock Blast vs. 4/0 Kyogre: 90.5% - 108%</li>
<li>+2 Rock Blast vs. 252/252 Bold Kyogre: 54.5% - 64.5%</li>
<li>+2 Rock Blast vs. 252/0 Manaphy: 69.5% - 83%</li>
<li>+0 Rock Blast vs. 248/0 Ho-Oh: 149.5% - 178.5%</li>
</ul>
<p>Rapid Spin is an option over Rock Blast or Hydro Pump, allowing Cloyster to clear entry hazards if necessary. It helps that the best spinblocker in Ubers, Giratina-O, cannot switch safely into Cloyster. Another option is Ice Shard, which can be used to revenge kill a +1 Rayquaza or Shaymin-S. Razor Shell is an option over Hydro Pump, but it misses some noticeable KOs.</p>
<p>Because Cloyster is so specially frail, it is almost mandatory to have either dual screen support or Wobbuffet as a teammate. A layer of Spikes is also crucial for some KOs. Deoxys-S can reliably provide both dual screens and a layer of Spikes. Arceus can provide both screens reliably, and can also burn physical attackers with Will-O-Wisp, easing setup for Cloyster. Latios can set up screens and then further weaken the opponent with Memento, giving Cloyster a free switch in, and likely a safe opportunity to use Shell Smash. Ferrothorn and Forretress can both supply Spikes as well, with the latter being able to spin away Stealth Rock, which otherwise severely hampers Cloyster. Ferrothorn is also valuable for its ability to threaten and wear down bulky Water-types, especially Kingdra, which are some of the best answers to Cloyster. Rain support is also required for Hydro Pump to pick up some KOs, so Kyogre should be paired with Cloyster.</p>
[Other Options]
<p>Hidden Power Fire can be used on the Shell Smash set to nail Ferrothorn, but should only be considered if Kyogre support can't be managed. Cloyster doesn't really have many options, since Shell Smash sweeping is the only thing it's good at. Cloyster can provide support with Toxic Spikes and Rapid Spin, but Forretress outclasses it. Focus Sash or White Herb can be used to give Cloyster some longevity, but it desperately needs the power a Life Orb provides. A gimmicky Clamp set could be used to get up a lot of entry hazards, but it is extremely situational, since many Pokemon in the Ubers metagame threaten Cloyster.</p>
[Checks and Counters]
<p>It should be kept in mind that Cloyster is incredibly frail on the special side, to the point where a -4 support Dialga will OHKO it with Draco Meteor after Stealth Rock. As such, pressuring Cloyster with special attackers will severely hamper its ability to get off a Shell Smash. In the event that Cloyster manages to set up, bulky Kyogre is perhaps the best counter to it, since it can take anything Cloyster can throw at it while at +2, and OHKO back with Scald. Similarly, 252 HP Manaphy can shrug off a +2 Rock Blast and KO back. Kingdra in the rain can outspeed Cloyster and OHKO it with a special attack. Needless to say, Cloyster cannot easily get around these Pokemon without team support. A physically defensive Ferrothorn can just barely take a +2 Icicle Spear and OHKO back with Power Whip. Choice Scarf Darkrai and Shaymin-S can both easily revenge kill Cloyster, although the latter must be wary of Ice Shard. Darkrai also has the added benefit of not being overly troubled by Wobbuffet, who could otherwise trap and kill a Scarfed revenge killer. Priority helps deal with Cloyster very well, so Arceus and Rayquaza make very good checks when running ExtremeSpeed. Scizor is also capable of revenge killing Cloyster after Shell Smash, Stealth Rock, and a few turns of Life Orb recoil. Vacuum Wave users, such as Lucario and Toxicroak, do a fine job dealing with Cloyster as well.</p>
