No-one here can tell you what Pokemon to use, since your likes and dislikes are different to everyone elses. I could, for example, tell you to use Lapras for the quad-resist to Ice to cover Torterra's 4x weakness to it, but if you don't like Lapras or have no way of getting it, then recommending it to you is pointless. The best thing to do is come up with your own ideas, post those ideas here, and then let us help you with them. We can't really do much if we don't know exactly what Pokemon we're dealing with.