>>21678640With the right team around it. Heatran synergizes almost perfectly with it. Parasect covers Heatran's ground, water and fighting weakness, Heatran covers Parasect's fire, flying, poison, bug and ice weakness. The rock weakness it the only thing to worry about, and there are other things to take that. You need a spinner though, since you'll be switching a lot.
My Parasect is Spore/Sub/Leech Seed/X-Scissor. Put something to sleep or sub on the predicted switch, seed something else and switch out to give your team passive recovery. With a bit of prediction and luck you can also drain down a Pokemon in a few turn if you sit behind a sub and spore in the right turns.