Originally Posted by Fat Ignitrua
Unnerve is a rather rare ability. Aerodactyl and Galvantula see nearly no play, and Tyranitar is better off with Sand Stream anyways. But yeah, I do agree with the 'croak suggestion, Protect is far more helpful. Also, Ice Beam is still quite helpful on Cress, it's just down to exactly how dragons murder you. And while I don't particularly second dropping Hammer Arm on Tornadus, Tailwind should definately be in there.
If you're having trouble with Rotom-W and Gastrodon, I recommend a Zapdos with Hidden Power Grass (unless you're really adamant about running the less used pokemon). Electric Gem OHKOs any Rotom-W investing significantly in speed, and Hidden Power Grass is one of those less used attacks for Gastrodon. You can even keep Tailwind!
The set is:
Zapdos @ Electric Gem
Modest: 4 HP/252 SpA/252 Spe
-Hidden Power [Grass]
Hammer Arm and Ice Beam are both valuable attacks that I've never looked back on wishing I'd replaced them with other moveslots. Ice Beam breaks subs that icy wind cant, and it also hurts dem dragons. Hammer Arm is important because it deals damage to threats that Tornadus has trouble with ordinarily (and the ones that outspeed will be most likely paralyzed at this point.)
The suggestion for HP grass Zapdos is cool, but i find the power behind it to be extremely lacking. non STAB base 70 is still a 2HKO on both gastrodon and rotom (seeing as how rotom and gastro normally run max HP. And for the tailwind suggestion, I've never really found myslef in a situation where i felt like tailwind helps me so imo its a waste for this team. This team spreads paralysis so fast it already outspeeds everything.