Rotom-C has always been a curious case. With Rotom-W and Rotom-H locked away in the higher tiers and Rotom-F being a more specialized threat in RU, Rotom-C finds itself stuck in the middle of the Rotom formes. However, this is by no means a bad thing. In a tier littered with powerful Grass- and Electric-type Pokemon, Rotom-C stands out with a great base 105 Special Attack and solid base 86 Speed, making it one of the best Choice Scarf users in RU. This is not all it can do, though; those same offensive stats make Rotom-C one of the most difficult Choice Specs users to switch into. Rotom-C can even put its solid resistances to good use with a solid utility set which takes more advantage of its twin base 107 defenses. All of these sets are further backed by the powerful Leaf Storm and great utility of Volt Switch, the latter of which makes Rotom-C one of the best pivots in the tier for offensive teams. Rotom-C was blessed in the ability department as well, as Levitate gives it a useful immunity to Spikes and Toxic Spikes, as well as Ground-type moves.
While it has great STAB options at its disposal, it has very little else to utilize offensively outside of Hidden Power. Rotom-C's strongest move, Leaf Storm, also has a severe drawback, as it cuts Rotom-C's Special Attack by two stages upon use, letting it become setup bait for many boosting sweepers. Rotom-C's typing lends itself to solid resistances, but weaknesses to Fire-, Bug-, and Ice-type moves hold it back defensively when combined with its low base 50 HP. The rise of threats such as Amoonguss and Druddigon have really hurt Rotom-C, as both resist its STAB options and can proceed to threaten it and its teammates with sleep and powerful attacks, respectively. However, do not let these drawbacks fool you into believing that Rotom-C is a bad Pokemon. It's one of the most versatile threats in RU and something that every team needs to prepare for.
Rotom-C is most commonly seen using a Choice Scarf, and for good reason. It has just about everything you could ever ask for in a Choice Scarf user. It has a great base 105 Special Attack, solid base 86 Speed that lets it outspeed most unboosted threats and even some boosted threats, a good set of resistances to switch in easily, and a momentum grabbing attack in Volt Switch.
Volt Switch is what makes this set amazing. Even if it's prepared for, Rotom-C can simply use Volt Switch early on to scout how the opponent intends on playing against it. Leaf Storm is Rotom-C's signature move and it also crushes virtually any Pokemon trying to block Volt Switch, including Rhydon, Golurk, Lanturn, and Manectric. However, you must take caution in utilizing Leaf Storm, as the resulting Special Attack drop will make Rotom-C setup bait for many dangerous sweepers. With Thunderbolt, Rotom-C becomes one of the hardest late-game cleaners to stop in RU, as its combination of Speed and power will be too much for any team that has had its checks and counters weakened or KOed over the course of the match. Despite this, Hidden Power Fire is still a worthy option. With it, Rotom-C gains the ability to effectively revenge kill Sceptile and Durant—both of which are very dangerous attackers in RU—in a moment's notice. Hidden Power Fire also prevents Ferroseed from walling Rotom-C. With Trick, Rotom-C is able to cripple walls such as Ferroseed and Clefable, two Pokemon that prevent Rotom-C from revenge killing its targets. With an important wall crippled by Trick, Rotom-C's teammates will find it much easier to execute their sweeps.Team Options & Additional Comments >>>
When donning a pair of Choice Specs, Rotom-C becomes one of the tier's most powerful wallbreakers. This Rotom-C is particularly effective against more balanced teams thanks to its immediate power, solid resistances, and good Speed.
Rotom-C seems outclassed by the likes of Typhlosion and Slowking, but it has one major move over them: Volt Switch. With a Choice Specs boost, Volt Switch hits much harder than you might originally think, and can give many opponents quite the surprise. Leaf Storm is just brutal on this set; virtually anything without a resistance to the move is 2HKOed at worst. Even some Pokemon that resist the move can be dealt with after Stealth Rock. Sceptile and Tangrowth are 2HKOed with Stealth Rock support alone while Galvantula gets OHKOed under the same conditions. Furthermore, Leaf Storm still hits relatively hard after the Special Attack drop on this set. That said, bulkier setup sweepers such as Gallade can still effectively set up after the Special Attack drop from Leaf Storm. Thunderbolt is preferred in the third slot to give Rotom-C a reliable STAB option to use as it has no drawbacks. Assuming a Modest nature, it also OHKOes Entei and Typhlosion and has an 87.5% chance to OHKO 4/0 Emboar after Stealth Rock. In spite of this, Hidden Power Fire is a viable option on this set. With the power boost from Choice Specs, Hidden Power Fire allows Rotom-C to run through the likes of Escavalier, Steelix, and Ferroseed. In the last slot, Trick is the main option as it lets Rotom-C cripple various walls for the remainder of the match. However, if you want both Thunderbolt and Hidden Power Fire, Trick can be eschewed to get the best of both worlds.Team Options & Additional Comments >>>
While Rotom-C is one of the best Choice item users in RU, one shouldn't forget its useful resistances to Electric-, Water-, and Grass-type moves. With this set, Rotom-C has more flexibility in its play, as it can check many top threats such as Slowking and Sceptile while still posing as a legitimate offensive threat, as it still has the same power as the Choice Scarf set. Rotom-C's STABs really shine here, as they hit many common physical attackers in RU for super effective damage.
Will-O-Wisp is Rotom-C's status move of choice on this set. The resulting burn cripples many physical attackers; Druddigon, Gallade, and Escavalier are just a few of the Pokemon shut down by a burn. However, be aware that most offensive variants of Gallade do run a Lum Berry. If slowing down the opposing team is more beneficial to its team, Rotom-C can opt to use Thunder Wave as its status move. This allows it to cripple physical and special attackers alike. Volt Switch is preferred in the next slot as it retains Rotom-C's overall utility and scouting abilities. If power is desired over general utility, Thunderbolt can be used over Volt Switch to give Rotom-C a way to go on the offensive without being forced to lower its Special Attack. Leaf Storm is an absolute must in the third slot, as it lets Rotom-C directly deal with the likes of Golurk and Rhydon without having to resort to burning them. Thanks to its ability to switch moves, Rotom-C can use Leaf Storm much more freely than either of the Choice sets, as it can Volt Switch out after using Leaf Storm. In the final slot, Rotom-C can use either Pain Split or Hidden Power Fire. Although it's fairly unreliable, Pain Split is Rotom-C's only means of recovery outside of Rest. Hidden Power Fire provides Rotom-C with a means of damaging Grass-types such as Sceptile, Ferroseed, and opposing Rotom-C.Team Options & Additional Comments >>>
Perhaps the easiest set to mold from its other sets is by utilizing the ChestoRest strategy. This can be achieved simply by placing Rest in the last slot of the utility set and switching the item to a Chesto Berry. This gives Rotom-C the ability to fully heal its HP and status once, thus quickly swinging momentum in the mid stages of the match. An Expert Belt set can be used, and it would compose of Volt Switch, Leaf Storm, Thunderbolt, and Hidden Power Fire (or Ice) to lure in and KO threats such as Escavalier, Klinklang, and Druddigon after using a STAB move. Lastly, a Rain Dance support set can be considered, as Rotom-C's typing fits very well into rain teams, giving such teams a solid resistance to Electric- and Grass-type moves.
As for individual moves, Rotom-C's offensive movepool is not impressive. Rotom-C's relevant offensive coverage starts and ends with its STABs and Hidden Power. Outside of the Choice Specs set, Hidden Power Ice doesn't have enough power to get through Druddigon's solid bulk fast enough. Signal Beam and Shadow Ball can be used to hit Psychic-types such as Uxie if desired, but they're only hitting about as hard as a neutral Thunderbolt. Any set trying to utilize Substitute is severely hindered by the fact that Leaf Storm cuts Rotom-C's Special Attack by two stages, thus usually forcing it to switch out afterward.
Rotom-C's support movepool is actually better. Toxic is a pretty neat looking option to cripple opposing walls, however, Rotom-C tends to attract walls that are immune to poison such as Ferroseed, Clefable, and Amoonguss. Rotom-C has both Thunder Wave and Confuse Ray, which can form a pretty frustrating parafusion set. However, this set lacks the overall reliability of Rotom-C's other sets. With decent Speed and solid defenses, Rotom-C can utilize a dual screens set. Such a set is hampered by the presence of strong Bug-, Fire-, and Ice-type moves, though.
Checks and Counters
To attempt to counter Rotom-C, you must first determine what set it's running, as each set typically sets out to do something completely different from the others. That said, Roselia and Amoonguss are decent initial switch-ins to scout a set as the only thing they really fear are Trick and Choice Specs-boosted Hidden Power Fire. Druddigon is also solid, as it isn't really crippled by Trick. However, it has to be wary of Will-O-Wisp and the rare Choice Specs-boosted Hidden Power Ice. As ironic as it might sound, Rotom-C can also be a good check to itself due to its resistances to Electric- and Grass-type moves. Outside of these, checks and counters generally vary with each set.
The Choice Scarf set gets walled by Amoonguss and Roselia, as even Hidden Power Fire will not break through them while both can threaten Rotom-C with their Poison-type STAB moves. Bulkier Fire-type Pokemon such as Entei and Emboar can stomach an Electric-type move and retaliate with a powerful Flare Blitz, and Entei can even revenge kill a weakened Choice Scarf Rotom-C with ExtremeSpeed. Without Hidden Power Fire, Ferroseed hard counters the Choice Scarf set, as the best Rotom-C can do to it otherwise is cripple Ferroseed with Trick. Druddigon can also take attacks from the Choice Scarf set with relative ease and it doesn't mind Trick nearly as much as other defensive switch-ins. The Choice Specs set has no true counters, as one correct prediction can seriously dent or KO Rotom-C's check. However, with the boost in power comes a drop in Speed, so revenge killing is much easier. Accelgor, Galvantula, Entei, and Moltres can all revenge kill Rotom-C. The last two can even come in directly to Leaf Storm thanks to their decent bulk and resistance to the move. Choice Scarf users such as Emboar, Braviary, and Medicham can also revenge kill Rotom-C.
The utility set doesn't really have "counters" in the strictest sense of the word because it simply aims to support its team, but its impact can be lessened by certain Pokemon. Roselia is a full stop to the set as it has Natural Cure to heal status afflictions, a 4x resistance to Leaf Storm, a 2x resistance to Volt Switch and Thunderbolt, and it has the special bulk to stomach Hidden Power Fire if Rotom-C chooses to carry it. Amoonguss and Ferroseed also fare well, but they have to be more careful around Will-O-Wisp as they don't have Natural Cure. Although it's relatively rare in RU, Choice Specs Altaria is a fine offensive response as it has Natural Cure to heal status, a 4x resistance to Leaf Storm, and the special bulk to handle Electric-type moves.