With this set, Rotom-W makes an excellent offensive support Pokemon and can use its good bulk and offensive power to check powerful Pokemon such as Excadrill, Kingdra, and Tyranitar. Hydro Pump is a great attacking move here, as it is very powerful and has excellent neutral coverage. It also decimates Ground-types and Tyranitar, both of which wouldn't mind taking a Thunderbolt. The fact that it gets a boost under rain allows Rotom-W to be both a nice rain partner and an even better rain check. Thunderbolt is a nice secondary STAB move, mauling the bulky Water-types that would otherwise not be threatened by Rotom-W. Thunderbolt also gives Rotom-W a more accurate attacking option than Hydro Pump. Thunder Wave is used here in order to cripple faster Pokemon and allow Rotom-W to better support its team. It is also nice to give Rotom-W a way to hit Pokemon that otherwise would not be very threatened by it, such as Latios. Will-O-Wisp is nice to cripple physical attackers, but paralysis is generally a more useful status condition.

Sitrus Berry is the main item on this set because it helps boost Rotom-W's survivabiity, allowing it to continue to be a threat to the opponent as well as granting it the ability to take multiple hits in a single turn when needed. Alternatively, Rotom-W may hold a Water Gem or an Electric Gem to power one of its STAB moves to net quicker KOs. The investment in bulk is used to let Rotom-W survive a Life Orb-boosted Giga Drain from Ludicolo and either cripple it with paralysis or hit it with a Thunderbolt; the rest of the EVs are invested in Rotom-W's Special Attack to allow it to hit the things it checks for solid damage. Hidden Power Grass is a nice option to hit Gastrodon, which is otherwise a huge problem for this set. However, the loss of a support move can hamper Rotom-W's effectiveness. Thunder is a nice option in rain to grant Rotom-W more power, but its accuracy is shaky outside of rain, which can be a problem. Another option for this set is Discharge, as it gives Rotom-W a spread move with a nice paralysis chance. However, there is a noticeable drop in power between it and Thunderbolt, and the fact that it can also hit your partner can be a huge problem as it either forces Rotom-W's partner to Protect or forces you to pair Rotom-W with a Pokemon with an immunity to Electric-type attacks.

Because Rotom-W is vulnerable to Grass- and Dragon-types that don't mind its attacks, Pokemon that can handle them such as Scizor and Abomasnow make for great partners. Scizor resists both Grass- and Dragon-type moves and can damage their users heavily with its Technician-boosted attacks. Abomasnow's STAB Blizzards can easily threaten both Grass- and Dragon-types, and it can also take care of Gastrodon with Giga Drain, making it another good choice. Other good partners include Hitmontop for its Intimidate support, Latios for its ability to outspeed other Dragon-types and beat Grass-types, and Tornadus for outspeeding all common Dragon-types and decimating things that can threaten Rotom-W with a Flying Gem-boosted Acrobatics. Pokemon such as Garchomp and Landorus can also be effective partners, as they appreciate Rotom-W's ability to check rain as well as its paralysis support; they also don't have to worry about hitting Rotom-W with Earthquake thanks to its Levitate ability.

With Choice Specs and maximum Special Attack investment, Rotom-W's Special Attack reaches a whopping 509, letting it dish out serious pain to just about anything it attacks. Hydro Pump is the main STAB attack here, and it is a great move to be locked into thanks to its great coverage and high power, which lets it heavily damage Pokemon such as Tyranitar and Scizor. Thunderbolt is the secondary STAB move and has nice coverage with Hydro Pump, eliminating pesky Water-types such as Jellicent and Suicune that don't mind a Hydro Pump. It also allows Rotom-W to be locked into a more reliable STAB move and not have to risk Hydro Pump's 80% accuracy. Thunder might seem like a strange option alongside Thunderbolt, but it serves an important purpose. Even if you are using Rotom-W outside of rain, Thunder is necessary to net important KOs against common rain Pokemon, making this set a much better rain check. Here are some damage calculations comparing the power of Thunder to that of Thunderbolt:

• 252+ SpA Choice Specs Rotom-W Thunderbolt vs. 0 HP / 4 SpD Ludicolo: 220-259 (73.57 - 86.62%) -- guaranteed 2HKO
• 252+ SpA Choice Specs Rotom-W Thunder vs. 0 HP / 4 SpD Ludicolo: 277-327 (92.64 - 109.36%) -- 56.25% chance to OHKO
• 252+ SpA Choice Specs Rotom-W Thunderbolt vs. 0 HP / 4 SpD Kingdra: 229-270 (78.69 - 92.78%) -- guaranteed 2HKO
• 252+ SpA Choice Specs Rotom-W Thunder vs. 0 HP / 4 SpD Kingdra: 288-340 (98.96 - 116.83%) -- 93.75% chance to OHKO

If you are uncomfortable using Thunder outside of rain, Trick is another good option, as it lets you cripple a Pokemon by locking it into a move, severely hampering its usability. Trick is also useful because it prevents Pokemon from effectively taking advantage of moves such as Fake Out and Protect. Hidden Power Grass is mainly used to eliminate Gastrodon, which is very important because Gastrodon is immune to both of its STAB moves and not only redirects but also gets a boost from Hydro Pump. Hidden Power Ice is also an option to be able to eliminate Salamence and Shaymin-S. However, Thunder is able to OHKO both of them, so keep that in mind when deciding whether to use it.

Volt Switch allows Rotom-W to fire off an attack while gaining momentum, but it is weaker than Thunderbolt and isn't able to be used as reliably due to forcing Rotom-W out when it is used. Another option for this set is Discharge, as it gives Rotom-W a spread move with a high chance to paralyze an opposing Pokemon. However, there is a noticable drop in power between it and Thunderbolt, and the fact that it can hit Rotom-W's partner can be a huge problem. This set really enjoys rain support, as not only does it grant Hydro Pump more power but it also allows Rotom-W to use Thunder reliably. The EVs allow Rotom-W to live a Life Orb-boosted Giga Drain from Ludicolo, which is even more important on this set because Rotom-W has a high chance to OHKO it in return with Thunder.

Pokemon such as Scizor and Tornadus that can reliably eliminate Grass- and Dragon-types make good partners for this set as well. Garchomp, Excadrill, and Landorus appreciate this set's ability to easily wear down defensive Pokemon so they can clean up late-game. They also enjoy the fact that they can use their powerful Earthquakes without worrying about hurting Rotom-W. Cresselia also makes for a great partner as it can provide the speed control that Rotom-W likes having. It also enjoys the fact that this set can easily destroy things such as Scizor and Tyranitar that would otherwise threaten it.

With a Choice Scarf set, Rotom-W can outspeed and beat faster threats such as Tornadus. Hydro Pump is one of the main STAB moves used, and it is a great attacking option due to its high Base Power and its impeccable coverage. It is also great because it can eliminate Ground-types which are looking to absorb a Thunderbolt or Volt Switch; it also hits Tyranitar, which otherwise would not be bothered by anything on this set. Thunderbolt is another great attacking option because it hits bulky Water-types such as Jellicent and Politoed and is more reliable than Hydro Pump due to its perfect accuracy. Volt Switch is a great option for picking off weakened Pokemon while maintaining offensive momentum. It is also a great way to bring in Pokemon such as Politoed to give your team an edge in weather wars. Trick is a great option to cripple defensive Pokemon that might try to take advantage of the fact that Rotom-W will be locked into a move. The fact that it disrupts the use of moves such as Fake Out and Protect is also a nice bonus. Hidden Power Grass is the main option on this set to get rid of Gastrodon, which is very important because Rotom-W has no way to get past it otherwise. However, Hidden Power Ice is an option to KO Shaymin-S and Salamence.

The EVs are very simple and are meant to make Rotom-W as fast and as powerful as possible. A Timid nature is slashed first in order to outspeed Jolly Choice Scarf Heracross, but if this benchmark isn't necessary for your team, a Modest nature can be used for more power, netting useful KOs such as an OHKO on Tyranitar outside of Sand. Thunder is an option over Thunderbolt, but it should only be used with rain support, as otherwise its accuracy will be too shaky. Sadly, due to the lack of investment in bulk, this set has more trouble switching into hits than others. This set works best on teams that are slower and need a way to take on fast attackers, so teams utilizing strategies such as Tailwind will likely be better served by another one.

Politoed makes for a great partner for this set, giving Hydro Pump a large boost in power and enabling Rotom-W to use Thunder instead of Thunderbolt. In addition, Politoed appreciates Rotom-W's access to Volt Switch, as it allows Politoed to perform better in weather wars. Pokemon that can defeat the Grass- and Dragon-types that don't mind taking on this set, such as Scizor, Abomasnow, and Tornadus, make for good partners. Cresselia makes for another good partner to this set as it can provide Helping Hand support, allowing Rotom-W to gain KOs that it might otherwise miss out on, such as an OHKO on Shaymin-S with Thunder.