 How to get all the Rotom forms in Pokemon Scarlet and Violet. First things first, you'll need a Rotom. You can catch one near Porto Miranda on this part of the map near the lighthouse. Once you have your Rotom, head over to Cascara for City and then head to this market stall to bid on the Rotom catalogue. This is a key item that will allow you to change your Rotom into all its different forms. Then all you have to do is make sure you have a Rotom in your party, head into your bag to find the Rotom catalogue and select which form you'd like to change your Rotom into.