Shaymin

Natural Cure
Cures status on switching out.
Type Tier
Grass BL
Statistics
Min- Min Max Max+
HP
100
- 341 404 -
Atk
100
212 236 299 328
Def
100
212 236 299 328
SpA
100
212 236 299 328
SpD
100
212 236 299 328
Spe
100
212 236 299 328
Name Item Nature

Choice Specs

Choice Specs Modest
Moveset EVs
~ Seed Flare
~ Psychic
~ Hidden Power Fire
~ Grass Knot / Rest / Hyper Beam
6 HP / 252 SpA / 252 Spe

Very limited movepool, but the power of Choice Specs Seed Flare should not be underestimated. Even Blissey won't enjoy switching in if it drops her Special Defense when she makes an appearance. Psychic helps against Poison types and Grass resisting Fighters, like Heracross, Breloom and Infernape. Hidden Power Fire covers Steels and other Grass-types. Although Fire offers the best coverage, HP Ground is a decent option as it finishes off Heatran, and other assorted Steels and Fires; Ice kills flying Dragons and also covers Shaymin's fellow Grassers.

Grass Knot is an option due to Seed Flare's low PP. Rest keeps Shaymin going for longer until her counter is eliminated. Hyper Beam is your best option against Salamence (unless you went for HP Ice), although it can leave Shaymin wide open to a revenge kill on the recharge turn.

Name Item Nature

Support

Leftovers Bold
Moveset EVs
~ Seed Flare / Grass Knot
~ Rest
~ Aromatherapy
~ Leech Seed / Grasswhistle / Hidden Power Fire
252 HP / 252 Def / 6 Spe

A change of pace here, with the focus being on defense and support rather than all out attack. As this version of Shaymin should stick around for quite some time, Grass Knot is listed as option over Seed Flare due to issues with PP. Rest and Natural Cure work very well together, although it requires Shaymin to switch out to remove the Sleep status. Aromatherapy is a rare and useful commodity which Shaymin uses quite effectively. In the last slot you can choose Leech Seed for some extra healing for Shaymin and its team mates; Grasswhistle has a mediocre 55% chance of sleeping the foe, but given Shaymin’s defenses, it’s not that bad. Finally, you can opt for Hidden Power Fire to hit Steels and Grassers. HP Ice or Ground are also viable options.

Name Item Nature

SubSeeder

Leftovers Timid
Moveset EVs
~ Substitute
~ Leech Seed
~ Seed Flare
~ Hidden Power Fire
252 HP / 6 SpA / 252 Spe

Once again, it is Seed Flare which helps to differentiate Shaymin from other Grass-types. This strategy is notorious for causing switches, and with Seed Flare's chance of slashing the opponents Special Defense, Shaymin may cause even more switching. Hidden Power Fire is recommended in the last slot so you can wear down Skarmory, who could otherwise switch in freely and Whirlwind away your Subs. It also maims Scizor who can hinder your strategy with U-turn.

Other Options

Not much. Synthesis is available for instant recovery, but with the prevalence of Sandstorm in OU play it only heals a meager 25% with each use.

EVs

For Choice Specs sets, max out Special Attack and Speed. Modest provides more power, but with Timid you have the option of outrunning the likes of neutral natured Salamence, Zapdos and Staraptor. Timid also guarantees Shaymin will outrun the likes of Porygon-Z, Lucario and Houndoom.

For the Tank/Support set, focus your EVs in HP and Defense, with a Bold nature.

SubSeeder works best with max HP and Speed.

Opinion

Shaymin’s movepool is extremely limited, and, as such, is almost a subset of Celebi’s, with Seed Flare and a subpar sleeping move thrown in. Because of this, everything that Shaymin can do is done by Celebi as well, and usually, the GSC legend does it better.

However, Shaymin's typing and Seed Flare mean that it can still be salvaged. Seed Flare is not to be underestimated; it has a big base power and has a good chance to pack twice the punch in the following turn because of its secondary effect, even if the first hit was resisted, which can make it rather difficult for the opponent to switch into Shaymin. Shaymin's pure Grass type means that it is not weak to Pursuit, unlike Celebi, and makes it able to take Gengar's Shadow Balls and maybe even a Bug move, since Shaymin is only 2x weak to Bug. The lack of a reliable recovery move (unlike Celebi, which sports Recover) is bad news for Shaymin, though.

Counters

Heatran will always counter the standard Shaymin, especially Choice Scarf versions, as they're not at risk from SubSeeding. Salamence works if Shaymin isn't carrying HP Ice, although Choice Specs Psychic has a good chance to 2HKO the Dragon. Skarmory and Scizor can both handle everything barring HP Fire, and can screw up the SubSeeder with Whirlwind or U-turn, respectively

The SubSeeder set is also countered by any faster Pokémon, especially one that has a super effective move on Shaymin. Pokémon with the move U-turn can remove the Substitute and switch out to a Pokémon that can counter Shaymin.

Against the Support and the Choice Specs set, Blissey and Cresselia can switch into Shaymin and threaten to Ice Beam it. If it has Grasswhistle, any Sleep Talker with a strong super effective move can switch in and scare Shaymin away.