Rayquaza is a Legendary Pokemon and is very rare in Project Pokemon, being one of the rarest Pokemon you can encounter in the wild. It is powerful and can learn some really strong moves, and most people use it to find the Legendary Pokemon Groudon and Kyogre, which there is a page about those two Pokemon as well. Rayquaza, like all legendaries have a 1/1000 chance of encounter, but you can up your chances of encountering Rayquaza by buying the "Other Legendaries" gamepass. Rayquaza is found by going to Cinnabar Volcano and going to the furthest house, thus talking to the guy in the red suit. He will give you a "hunch" and you will find Rayquaza in this hunch. But the hunches change every 10 minutes, so you will have to look back at this place after every 10 minutes.