Other Options

Choice Specs can be used to trade Speed for power, letting Rotom-C punish foes like Registeel harder while pivoting. However, Nasty Plot is largely more consistent at wallbreaking, and Raikou and Magnezone generally outclass it as an Electric-type Choice Specs pivot. Tera Water can be used to turn Rotom-C's Fire weakness into a resistance, letting it check Volcanion in a pinch. Discharge can be used over Thunderbolt in order to fish for paralysis against switch-ins like Cyclizar, though it becomes less likely to 2HKO Noivern and, after a Nasty Plot Boost, Cresselia.

Checks and Counters

Dragon-types: Cyclizar and Hisuian Goodra can comfortably take Rotom-C's attacks due to its lacking coverage, letting them freely remove entry hazards or KO it with Draco Meteor, respectively. However, both must be wary of being statused or given a Choice Scarf via Trick. While they don't like taking a Volt Switch or Thunderbolt, Noivern has a 4x resistance to Leaf Storm and can wear Rotom-C down with its powerful attacks. However, Rotom-C can simply use Volt Switch to pivot out against them and its other defensive checks as they switch in.

Grass-types: Wo-Chien completely walls Rotom-C and is able to wear it down with Ruination and Knock Off. Pain Split Rotom-C can eventually beat it one-on-one, but it becomes significantly weakened afterwards. Similarly, Chesnaught can safely switch into Rotom-C's attacks, heal off any damage with Synthesis, and freely set up Spikes. However, neither like being burned nor being given a Choice Scarf.

Special Walls: Specially bulky Pokemon, like Umbreon and Blissey, can shrug off Rotom-C's attacks and heal off the damage, all while wearing it down with Toxic for the former and Seismic Toss for the latter. They both must be wary of Trick, however, while Umbreon can be muscled through by Nasty Plot variants.

Faster Revenge Killers: Rotom-C's middling Speed makes it vulnerable to being revenge killed by faster Choice Scarf users, such as Galarian Zapdos, Terrakion, and Gengar. Boosted Bisharp can take it out with Sucker Punch; however, it must be mindful of Will-O-Wisp.