Okay, you might be confused here, because it's Rotom, and Rotom is mediocre right? Not really. It is actually quite usable in OU. Reasons are outlined in the skeleton. Give it a shot. It won't disappoint.
Kekeke
[Overview]
<p>The unadorned Rotom has long been overshadowed by its alternate formes. However, in the fifth generation, it alone retains one of the defining attractions of the appliance family when it was first introduced: the Ghost typing. Possessing the treasured ability to block Rapid Spin and simultaneously keep offensive momentum through Volt Switch, Rotom’s great typing and speed enables it to become both an offensive spinblocker and a revenge killer. Unfortunately, Rotom is still very frail, and its base 95 Special Attack fails to outshine the rest of the metagame. In conclusion, play Rotom to its unique strengths, or don’t use it at all.</p>
[SET]
name: Choice Scarf
move 1: Volt Switch
move 2: Shadow Ball
move 3: Hidden Power Ice / Thunderbolt
move 4: Trick
item: Choice Scarf
nature: Timid
evs: 4 HP / 252 SpA / 252 Spe
[SET COMMENTS]
<p>Rotom's excellent typing, access to Volt Switch, and usable Special Attack and Speed stats make it a surprisingly effective revenge killer as well as a spinblocker. With a Choice Scarf, it reaches 463 Speed, outspeeding +1 Dragonite, Gyarados, Adamant Haxorus, and Salamence. While it may appear that Gengar or Mismagius could play this role better, Rotom's resistances and access to Volt Switch differentiate itself from the aforementioned alternatives. With a Choice Scarf, Rotom can outspeed and OHKO one of the most common Rapid Spin users, Starmie, with Volt Switch, although it needs to be careful when switching in for fear of an OHKO from Hydro Pump. Volt Switch also allows Rotom to be one step ahead of Pursuit users, who would easily pick off Rotom otherwise.</p>
<p>Volt Switch is Rotom's main attack, allowing it to keep offensive momentum and OHKO Gyarados. Shadow Ball severely dents Celebi and Gengar, while Hidden Power Ice allows Rotom to revenge kill slightly weakened Dragon-type Pokemon such as Salamence and Dragonite. For a stronger STAB attack, Thunderbolt is an alternative option, although coverage is sacrificed if you choose to run it. Finally, Trick rounds out the set by allowing Rotom to cripple special walls that would switch in, such as Blissey and Jirachi.</p>
[ADDITIONAL COMMENTS]
<p>Will-O-Wisp can replace a move other than Volt Switch for a quick burn. However, being Choice-locked on a non-damaging move defeats the purpose of maintaining momentum. A Modest nature can be used instead of a Timid one, but Rotom really enjoys its strategic base 91 Speed, which should be taken advantage of as much as possible. </p>
<p>Rotom fears Pursuit more than the plague. It should keep an eye out for strong Pursuit users and Volt Switch out of such confrontations. Lucario and Terrakion are excellent teammates to switch into Pursuit, setting up on the omnipresent Tyranitar. Scizor is also an excellent Pokemon to run alongside Rotom for the acclaimed U-turn + Volt Switch combo. Steel-type Spikes users such as Skarmory, Forretress, and Ferrothorn can easily switch into Ghost- and Dark-type moves aimed at Rotom and set up Spikes, which Rotom can keep on the field by blocking Rapid Spin. Virizion takes a pittance from Rotom's attacks and can set up on it, a weakness easily remedied by the inclusion of teammates such as Jirachi, Latias, or Latios.</p>
[Other Options]
<p>Rotom could potentially run a status platform set with Will-O-Wisp / Discharge / Volt Switch / Pain Split, but it is generally too frail for such a set. A Substitute + Pain Split is largely outclassed by Gengar, though a Substitute + Charge Beam set may be viable. While Rotom's stats leave much to be desired for these strategies, being able to set up on Blissey and Chansey is a large selling point.</p>
[Counters]
<p>Tyranitar is Rotom's worst enemy. It can switch into any attack, take a negligible amount of damage, and remove Rotom via Pursuit if it is Choice-locked into something other than Volt Switch. Scizor can do similarly if it comes in on a resisted move. Virizion takes very little from Rotom's attacks and can set up using Calm Mind with impunity. Gastrodon and Swampert are immune to Volt Switch and take little from its coverage moves, while Blissey and Chansey wall Rotom. These walls all need to watch out for Trick, however, as having a Choice item could cripple them for the rest of the match.</p>
Kekeke
[Overview]
<p>The unadorned Rotom has long been overshadowed by its alternate formes. However, in the fifth generation, it alone retains one of the defining attractions of the appliance family when it was first introduced: the Ghost typing. Possessing the treasured ability to block Rapid Spin and simultaneously keep offensive momentum through Volt Switch, Rotom’s great typing and speed enables it to become both an offensive spinblocker and a revenge killer. Unfortunately, Rotom is still very frail, and its base 95 Special Attack fails to outshine the rest of the metagame. In conclusion, play Rotom to its unique strengths, or don’t use it at all.</p>
[SET]
name: Choice Scarf
move 1: Volt Switch
move 2: Shadow Ball
move 3: Hidden Power Ice / Thunderbolt
move 4: Trick
item: Choice Scarf
nature: Timid
evs: 4 HP / 252 SpA / 252 Spe
[SET COMMENTS]
<p>Rotom's excellent typing, access to Volt Switch, and usable Special Attack and Speed stats make it a surprisingly effective revenge killer as well as a spinblocker. With a Choice Scarf, it reaches 463 Speed, outspeeding +1 Dragonite, Gyarados, Adamant Haxorus, and Salamence. While it may appear that Gengar or Mismagius could play this role better, Rotom's resistances and access to Volt Switch differentiate itself from the aforementioned alternatives. With a Choice Scarf, Rotom can outspeed and OHKO one of the most common Rapid Spin users, Starmie, with Volt Switch, although it needs to be careful when switching in for fear of an OHKO from Hydro Pump. Volt Switch also allows Rotom to be one step ahead of Pursuit users, who would easily pick off Rotom otherwise.</p>
<p>Volt Switch is Rotom's main attack, allowing it to keep offensive momentum and OHKO Gyarados. Shadow Ball severely dents Celebi and Gengar, while Hidden Power Ice allows Rotom to revenge kill slightly weakened Dragon-type Pokemon such as Salamence and Dragonite. For a stronger STAB attack, Thunderbolt is an alternative option, although coverage is sacrificed if you choose to run it. Finally, Trick rounds out the set by allowing Rotom to cripple special walls that would switch in, such as Blissey and Jirachi.</p>
[ADDITIONAL COMMENTS]
<p>Will-O-Wisp can replace a move other than Volt Switch for a quick burn. However, being Choice-locked on a non-damaging move defeats the purpose of maintaining momentum. A Modest nature can be used instead of a Timid one, but Rotom really enjoys its strategic base 91 Speed, which should be taken advantage of as much as possible. </p>
<p>Rotom fears Pursuit more than the plague. It should keep an eye out for strong Pursuit users and Volt Switch out of such confrontations. Lucario and Terrakion are excellent teammates to switch into Pursuit, setting up on the omnipresent Tyranitar. Scizor is also an excellent Pokemon to run alongside Rotom for the acclaimed U-turn + Volt Switch combo. Steel-type Spikes users such as Skarmory, Forretress, and Ferrothorn can easily switch into Ghost- and Dark-type moves aimed at Rotom and set up Spikes, which Rotom can keep on the field by blocking Rapid Spin. Virizion takes a pittance from Rotom's attacks and can set up on it, a weakness easily remedied by the inclusion of teammates such as Jirachi, Latias, or Latios.</p>
[Other Options]
<p>Rotom could potentially run a status platform set with Will-O-Wisp / Discharge / Volt Switch / Pain Split, but it is generally too frail for such a set. A Substitute + Pain Split is largely outclassed by Gengar, though a Substitute + Charge Beam set may be viable. While Rotom's stats leave much to be desired for these strategies, being able to set up on Blissey and Chansey is a large selling point.</p>
[Counters]
<p>Tyranitar is Rotom's worst enemy. It can switch into any attack, take a negligible amount of damage, and remove Rotom via Pursuit if it is Choice-locked into something other than Volt Switch. Scizor can do similarly if it comes in on a resisted move. Virizion takes very little from Rotom's attacks and can set up using Calm Mind with impunity. Gastrodon and Swampert are immune to Volt Switch and take little from its coverage moves, while Blissey and Chansey wall Rotom. These walls all need to watch out for Trick, however, as having a Choice item could cripple them for the rest of the match.</p>
