>>13115118For the counter Gengar you're gonna have to get a decent IV'd Gastly with the right nature (hasty, timid, speed is probably the best thing you can do here since Counter has -5 priority) from Fire Red or Leaf Green, and teach it counter from the move tutor there, then pass it all the way to BW/BW2. You can EV train it in whatever gen you want.
Anyway for more suggestions..How about a Cradily toxic tank? Its not the most efficient, but with storm drain you can absorb water attacks (normally a neutral attack against it) or with suction cups you can stop any Roars (I doubt anyone will use a Roar strategy though). I have seen Cradily take on Outrages and survive with more than half its HP from Dragonites though. With Recover and Protect, you can get a pretty decent Toxic strat going. Storm drain will allow you to switch into water types as well.
