Moves
This variant of Abomasnow aims to offer as much utility as it can get into a single set. Leech Seed is Abomasnow's main recovery move and provides passive damage in addition to hail, a combination that wears down the opposing Pokemon at a significant rate. The recovery granted by Leech Seed also aids Abomasnow's teammates if it is forced out by a powerful Pokemon such as Infernape. Abomasnow is also a good user of this move because its secondary Ice typing can discourage opposing Grass-types from trying to absorb Leech Seed. Protect pairs nicely with Leech Seed, as it allows Abomasnow to gain additional recovery for free while the opposing Pokemon is slowly losing its health. It also scouts which move a Choice item user will lock into, which is especially useful against strong super effective attackers like Choice Band Tyranitar and Scizor, and can also be a nice tool against Gyarados lacking Stone Edge and Taunt, as it ensures that Abomasnow can't be hit by Bounce.
Wood Hammer is the strongest Grass-type STAB attack available to hit Water-types that Abomasnow is supposed to counter. It also threatens Tyranitar with a potential OHKO and 2HKOes maximum HP Clefable, which could be tempted to switch in and deny Abomasnow's Leech Seed. Ice Shard OHKOes Flygon and non-Yache Berry Dragonite after Stealth Rock damage and a round of hail while dealing substantial damage to Pokemon such as Gliscor, Roserade, and Latias and threatening to revenge kill severely weakened Pokemon. Blizzard is an option to punish defensive variants of Zapdos, Skarmory, Togekiss, and Hidden Power Fire Celebi in case they're trying to fight Abomasnow while being a significantly stronger move overall.
Set Details
The recovery provided by Leftovers is invaluable for Abomasnow's survivability. 252 EVs in Attack and an Adamant nature are needed to get the aforementioned KOs with Wood Hammer and Ice Shard. The remaining EVs are placed into HP and Special Defense to retain sufficient bulk to handle most Water-types. Investing in Speed can be considered to get the jump on uninvested Swampert, Clefable, and Tyranitar. 16 EVs in Speed is usually the minimum if outspeeding those Pokemon is desired, but more EVs can be spent to outspeed Skarmory and Pokemon that sit around the base 70 Speed tier, mainly Tyranitar. Alternatively, if Blizzard is chosen over Ice Shard, Abomasnow can use a more bulky spread of 252 HP / 4 Atk / 252 SpD and a Sassy nature to get as much special bulk as possible, which allows Abomasnow to check Rain Dance Kingdra, Choice Scarf Latias, and offensive variants of Rotom-A more effectively.
Usage Tips
Bring Abomasnow in on foes it is suited to handle, mainly Water-types such as Starmie, Swampert, Suicune, Empoleon, and Milotic. Abomasnow can also take care of Raikou lacking Aura Sphere, Zapdos without Heat Wave or Hidden Power Flying, and most variants of Gliscor. From there, it can spread Leech Seed and get chip damage on the opposing Pokemon, which, in tandem with hail and Protect, can quickly wear down Steel-types, which are tempted to come in on Abomasnow. Depending on the opposing team, sending Abomasnow out as soon as possible to set up hail early can be a good idea, especially if the opponent hasn't set up Stealth Rock yet and cannot change the weather. The ability to induce hail upon entry can be critical against Pokemon such as Kingdra in an emergency situation. If Abomasnow packs Ice Shard, it can be used as a revenge killer to weakened Pokemon and make sure that Flygon and non-Yache Berry Dragonite locked into Outrage won't cause any more trouble.
Team Options
Abomasnow has a much easier time coming onto a field cleared of Stealth Rock and any other form of entry hazards. Therefore, Starmie makes for a great teammate due to its access to Rapid Spin and ability to keep Infernape, Heatran, and some Jirachi variants in check. Tentacruel is another notable spinner that pairs nicely with Abomasnow, as it is also able to deal with Fire-types, can set up and absorb Toxic Spikes, and can make use of Knock Off to remove the opposing Pokemon's Leftovers, which, if combined with hail and Leech Seed damage, wears down opposing Pokemon at an extremely fast rate. Nidoqueen is a good partner as well to absorb and set Toxic Spikes while serving as a check to Tyranitar and Fighting-types like Lucario and Infernape. Gliscor also does a good job at handling these threats and benefits from hail damage, as the residual damage enhances its stallbreaking capabilities. Defensive Jirachi is another noteworthy stallbreaker that appreciates hail support when trying to wear down the opposing team with Iron Head, as even opposing Steel-types such as Bronzong have trouble dealing with it if their Leftovers recovery is denied by hail. It also handles dangerous Pokemon such as Gengar and Latias and can support Abomasnow with Wish. Unlike most Pokemon, Clefable isn't bothered by hail at all due to its ability Magic Guard and can make good use of Knock Off, heal its teammates with Wish, and serve as an answer to Pokemon such as Heatran, Zapdos, and Latias that could force Abomasnow out. Skarmory brings another form of passive damage in Spikes and can check a large number of physical threats, namely Metagross, Scizor, and Gyarados. Since Abomasnow is unable to discourage opposing Skarmory from setting Spikes freely without Blizzard, Magnezone can be considered to circumvent this issue and to deal with other troublesome Steel-types such as Scizor and Jirachi.
Other good defensive teammates for Abomasnow include Latias, which serves as a competent answer to Infernape, Breloom, Heatran, and Zapdos while passing Wish. Rotom-A is also a valuable teammate due to its reliability at spinblocking and checking Steel-types such as Metagross, Scizor, physical Jirachi, and Bronzong. Zapdos also deals nicely with the aforementioned Steel-types and Fighting-types like Breloom. Finally, a dedicated hail team featuring Walrein is doable, although stacking Ice-types that share several weakness, mainly to Stealth Rock, comes with synergy issues.