I"m not going to post a set this time since it's late and my ideas have already been posted. Right now, I'm in huge favor of Latios / Latias. They can effectively counter Breloom, a pokemon that can easily be picked to give us major headaches. They also handle Keldeo / Heatran well, resisting their attacks and then hitting hard. There really isn't any problems with Scizor, since Zor is walled by Rotom-W, nor should there be any problems with Ttar, for the same reason. If need be, we can choose a fighting type later (in fact, we should, to counter any extra steels) to counter Blissey / Chansey / Special walls.