Groot

Hello, I'm new here, my name is Shannon. I just started this game recently, and it's a very well done game, I love the story line. However, it seems I am stuck. I need to get the old power plant on, but I can't beat Shade! His gengar always kills me! My venasaur, primeape, and swanna are level 36 and my arbok and drifblim are level 37. Is it just that I need to level them up more? I beat Magma Gang just fine, and Maxwell's pokemon were a lot higher level than mine. I also had no problem with Florina (beat her on my first try, I was very proud since it's taken my brother forever to do so), and it only took my two tries with Shelly. If it is that I need to level them up, can someone suggest the best place to do so?