Dear user Electrolyte.
In This post, you recommended a Special Defensive Rotom-W with a spread of 252 HP / 4 SpA / 252 Spe. This EV spread is incorrect, because you have placed no EV's into the Special Defense department. I believe the correct spread is 248 HP / 28 SpA / 232 SpD where the 28 Special Attack EV's are used for KOing all Max HP Gliscors, as the user has only one way of dealing supereffective damage to it, whereas the only supereffective move he has against Gliscor is CB Dragonites Waterfall. Thank you for your time.
Sincerely,
Dr Ciel.