Rotom was released at GoFest! So far, the only form that’s been confirmed is Rotom-Wash. That said, the release of one means that they’re all coming, so might as well discuss every last one now!
Note: Other than Rotom-Wash, all information here has been datamined, and as such it's possible that anything could change at any time before release. Don't take this as gospel, just potential guidance!
Base Rotom is an Electric/Ghost-type Pokémon with these stats
The other Rotoms all share stats with each other, and Rotom's base Electric typing, but they have higher stats than Base Rotom.
Rotom-Heat is Electric/Fire, Rotom-Wash is Electric/Water, Rotom-Mow is Electric/Grass, Rotom-Frost is Electric/Ice, and Rotom/Fan is Electric/Flying.
They also share a large portion of their moveset. All but Fan learn:
- Fast Moves: Astonish and Thunder Shock
- Charged Moves: Thunderbolt and Thunder
What makes them unique, though, is their movesets. In addition to the listed moves, Heat gets Overheat, Wash gets Hydro Pump, Frost gets Blizzard, and Base gets Ominous Wind.
Rotom-Fan trades in Thunder Shock for Air Slash and also learns Ominous Wind, making it unique in being the only Rotom with a special fast move.
Rotom-Mow, in the main series, has Leaf Storm as its signature move. However, as that's not implemented in GO yet, it just has Rotom's moveset of Astonish/Tackle+Ominous Wind/Thunderbolt/Thunder. However, it's safe to assume that by the time Mowtom gets released, it'll come with Leaf Storm. Leaf Storm's a Grass-type Overheat clone in the main series, so it's safe to assume that it'll be the same way here.
So....how good are they?
So here's the sad part, then. With 204 attack, Rotom's almost immediately off the table as a raid attacker. The current best non-Shadow attacker is Electivire, with 16.735 DPS. Non-base Rotom, running Thunder Shock + Thunderbolt, is significantly worse, down at 12.881 DPS. This puts it below other things that you probably aren't using, like Thunder Fang/Wild Charge Arcanine (13.198 DPS) and Thunder Shock/Wild Charge Raichu (13.273 DPS). Base Rotom is even worse, at 11.811 DPS. Given that you need a full-type moveset to be competitive, you can basically write off any non-Electric utility Rotom may have, too.
For all cases, we're going to assume Rotom will use Thunder Shock as its fast move, and then Thunderbolt + (the form's unique move) as a moveset. Let's run through them one by one but....don't get too excited. We're going to exclusively focus on Great League here, as none of them are positioned particularly well for Ultra, and they don't make it anywhere near the requisite CP to compete in Master League.
Thunder Shock + Thunderbolt and Hydro Pump
Well, it's got some Great League wins, at least? It's an Electric-type, so it handles Azumarill, Skarmory, Lapras, and Dewgong. Hydro Pump also lets it handle Probopass and Stunfisk, and it can take down Bastiodon with a little bit of prior chip damage. What's it lose to? Uhh...pretty much everything else. The defensive typing is solid, but the low bulk holds it back a lot. Frankly, Rotom-Wash in GO is more or less a bad version of Lanturn.
Thunder Shock + Thunderbolt and Overheat
Notably better than Wash, actually! While its typing leaves it with a crippling double weakness to Ground (dies to Whiscash and Toxicroak) and single weak to Water (dies to Swampert), it retains some of Wash's wins and gains a number of notable ones! A fast Overheat can let it take out Grass-types without too much trouble and a Charm resistance can let it take down Pokémon like Wigglytuff and Clefable pretty consistently. A little energy advantage lets it beat Azumarill in the 2-shield and 0-shield, but it needs a lot of energy to take the 1-shield.
Thunder Shock + Thunderbolt and Blizard
Ice-type has really bad defenses, and that does this Rotom form absolutely no favors. Frost is basically Wash, but with a few other random losses, and it can technically beat Altaria (but it's close). Unlike Heat, you can't really handle Grass-types other than Tropius (and even then you lose to Razor Leaf variants). Might wanna leave this one behind.
Air Slash + Thunderbolt and Ominous Wind
I lied when I said they'd all be running Thunder Shock. Fan learns Air Slash instead. This Rotom variant is great at beating Grass-types and Fighting-types, while holding onto that Skarmory win. However, as a Flying-type, you suddenly take super effective damage from Ice Beam, meaning you lose to Azumarill. There are better Flying-types. It's not worth using this one.
Thunder Shock + Thunderbolt and Ominous Wind
STAB Ominous Wind is...kinda neat, actually? It lets you take out Medicham and Deoxys-Defense, which the other forms can't claim. But lower bulk than the rest combined with mediocre defensive typing (you only barely beat Toxicroak) leaves this Rotom pretty sad.
Rotom-Mow doesn't have its special move yet, so it's hard to analyze this one. However, assuming Leaf Storm is a cloned Grass-type Overheat (130 Power/55 Energy/100% chance of -2 Attack), it....probably wouldn't be that special. While it's nice that it resists Water, taking super effective damage from Ice (hi, Ice Beam Azumarill) and neutral from Flying is hard. Kinda makes you wonder why you're even using an Electric-type at that point.
While we've only seen Rotom-Wash so far, and they're....not that good....they're still exciting! Rotom's a cool lil mon that holds a couple unique typings. While they're probably not great at anything, they're interesting, and they're perfectly fine choices if you've got an affinity for Rotom.