I'm actually starting to belive that Rotom-W might be suspect...
Why?
Stat Distribution:
50/65/107/105/107/86
This allows Rotom-W a massive amount fo flexibility to fill different roles. You can tell this just from looking at viable items:
Choice Scarf
Choice Specs
Life Orb
Leftovers
Rotom-W hits like... well, a household appliance being thrown at your head, and has rather impressive bulk, especially with HP investment [Or Defense Investment and Pain Split]
Typing and Ability:A MASSIVE contributor to Rotom-W's potential suspect status. Let's look at it this way. Water/Electric [With Levitate] give the following benifits:
ONE x2 weakness.
STAB Hydro Pump, which is brilliant in the current metagame, filled with Ground/Rock types, and Rain.
STAB Electric attacks, which is brilliant in a metagame filled with Water types... and Rain again.
Resistances to common attacking types: Fire, Ice, Water, Ground [Immunity] and Flying [Somewhat useful]
Movepool:
Viable moves that Rotom-W can use:
Discharge
Thunderbolt
Thunder
Charge Beam
Substitute
Volt Switch
Thunder Wave
Hydro Pump
Will-O-Wisp
Pain Split
Trick
Rest
Sleep Talk
Snatch [Should get more love..]
Reflect
Light Screen
Confuse Ray
----
Coverage Moves:
Hex
Shadow Ball
Dark Pulse
Signal Beam
Hidden Power
That's a massive and diverse movepool.
You switch in expecting a Volt Switch Rotom, and it throws up a Subtitute.
You see Lefties.
So you expect SubCharge after that? Nope, Rotom-W hits you with a Hydro Pump or Thunder, or even Status on your switch-in to that set.
--
Expect SubCharge next game? Then your Subcharge check gets blasted away by a Specs Hydro Pump.
Switch Tyranitar in to change the weather and stop Rain-Boosted Hydro Pumps and 100% accurate Thunders? Cry as Rotom-W Volt Switches to Politoad, ridding you of your sand, or as Rotom-W Will-O-Wisps.
About the only checks to Rotom-W are Grass-types, as they resist both STABS, and are it's one weakness.
However, Grass is a terrible attacking type, and if a Rain Team dosen't have a team member somewhere that can take on Ferrothorn/Virizion/Breloom, such as MultiScale Dragonite, Tornadus, or Thunderus, then it DESERVES to lose.
Then there's Rotom-W + Scizor. They resist each other's only weakness, both have a significant amount of power [Especially with Choice Items], both can heal [Roost and Pain Split] and can interchange with Volt Switch and U-Turn all day long, while hazards and the damage they put out whittles your team away.
And don't think about stopping Rotom-W's Volt Switches with a Ground type, as you'll eat a Hydro Pump.
I'll need to do some calcs later, but I don't have the time.
However, I feel that Rotom-W should be brought up to the plate to be discussed, as Im personally finding it as large a thorn as Thunderus, if not larger, especially on Rain teams.