[SET]
name: Rain Dance
move 1: Rain Dance
move 2: Thunder
move 3: Draco Meteor
move 4: Hydro Pump/Surf/Slack Off
item: Life Orb/Damp Rock *Removed Leftovers
nature: Timid
ability: Shield Dust/Static
evs: 248 HP/ 8 SpA/ 252 Spe
[SET COMMENTS]
As a thundercloud dragon, Cyclohm is naturally suited to thrive in the rain. It's tremendous defenses and valuable resistances make it fairly easy to come in and cause switches, giving it a free turn to set up Rain Dance.
Once rain is up, Cyclohm will be ready to sweep with its high-powered attacks. Thunder will most likely be your main attacking option, due to STAB and its 100% accuracy in rain. Hydro Pump gets pseudo-STAB in rain, making it just as powerful as Thunder in case any Ground-types think they can come in and force Cyclohm out. Hydro Pump's 80% accuracy is a little shaky, though, in which case you may opt for Surf's 142 BP in Rain and its 100% accuracy for a little more confidence at the expense of some power. The Electric/Water attacking combo is resisted by Dragon and Grass-types only, so Draco Meteor fills the last spot as Cyclohm's only real option to hit them if you predict they'll try and set up as you switch, but it will typically be used in last-ditch situations.
The choice of item is completely dependent upon what role Cyclohm is playing on the team. Life Orb will guarantee you the 2HKO on Metagross switch-ins with Thunder and on Mixpert with Hydro Pump followed by Draco Meteor. It also OHKOs Dugtrio, Mamoswine, non-Scarf Heatran, and Hippowdon with Hydro Pump and any Dragon-type with Draco Meteor. If you need Cyclohm mainly for being a sturdy Rain Dancer and not so much for sweeping, then Damp Rock is the better option. If you do choose Damp Rock, then Slack Off should be in that fourth moveslot so that Cyclohm can heal itself as it switches in multiple times to set up Rain Dance.
The EVs are similar to the Life Orb set, except that there have been 48 EVs moved from SpA to HP to help better survive the hard-hitting attackers that will be switching in to take Cyclohm down. With the higher-powered attacks, though, the set hits just as hard, if not harder. 419 HP is just shy of losing an extra point to Life Orb recoil, and it also means you'll always survive an EQ at full health from Metagross, CB Dugtrio, CB Tyranitar, Flygon, Salamence, and Swampert, all of which can be defeated one-on-one with Life Orb. You'll also survive an Ice Beam from Life Orb Starmie or non-Life Orb Porygon-Z, both of which you can OHKO with Thunder. Max Speed allows you to speed tie with Mamoswine and other base 80s and outrun neutral nature base 90s, notably Adamant Lucario, who has a 66% chance of being OHKO'd by Thunder.
This Cyclohm works well on standard Rain Dance teams, naturally, but it also does well on its own. If you aren't running dedicated Rain Dance, having Blissey on hand to take on the special attackers like Starmie, Scarftran, and Stratagem that would hinder a sweep is useful. Gyarados can come in on anything Scarftran will be throwing at you bar Explosion and Bronzong can take on Starmie's assault and scare off Stratagem with Gyro Ball. If you are running dedicated Rain Dance, Kingdra can come in and revenge anything that takes Cyclohm down or set up Dragon Dance while the opponent switches out and sweep on its own. Cyclohm's bulk along with Slack Off will allow it to take a lot of pressure off its other teammates to set up Rain Dance, meaning you will be able to put additional attacking moves or possibly additional pokemon into the classic Rain Dance mold, so feel free to experiment. If you do run Slack Off over a water attack, though, be sure to have something that can come in quickly on Magnezone so that it doesn't get a chance to set up effectively. Rotom-W is a good choice here, as it resists most everything Magnezone usually runs and carries the Hydro Pump that was sacrificed for more longevity. Mixdra can do the same thing and gets the Swift Swim bonus, but it will be taking a neutral rather than resisted hit from a very powerful Thunderbolt as it breaks the Sub.