Manakan Castform, the Wild Weather Pokemon [According to urban legend,] Castform is an artificial Pokemon created by [a mythical scientist] to finely control the weather. While these Castform do have a higher level of control than their Hoenn cousins, they are also far more erratic and delight on bringing down chaotic weather down all across Manaka.
Types: Flying Signature Ability: Weather Report — This Pokemon's form changes with the weather, and the weather changes with this Pokemon's attacks.
In specific, after a Pokemon with Weather Report attacks with a Water, Fire, Rock, Ice, or Poison move, it sets up the corresponding weather if that wasn't the last weather that Pokemon set by any means. Additionally, * Under Rain and Primordial Seas, Castform becomes its Rainy Form as usual, but under normal Rain, its fire moves are not depowered. * Under Sun and Desolate Lands, Castform becomes its Sunny Form as usual, but under normal Sun, its water moves are not depowered. * Under Hail and Snow, Castform becomes its Snowy Form as usual. * Under Sandstorm, Castform becomes its new Dusty Form. * Under Acid Rain and Fog, Castform becomes its new Smoggy Form, changing itself to the Poison type. In Fog, Castform's accuracy is not dropped and Weather Ball becomes Poison type. * Under Delta Stream, or under Tailwind with no other Weather, Castform's Weather Ball changes into the Flying type and doubles in power (and remains its Tornado form).
Mechanically, I'm back and forth on if the Weather Forms should keep the Flying type. The strongest thing holding me back is I did want to keep the Sunny, Rainy, and Snowy forms the same designs, which is going to cause issues if they have different types. I'm increasingly thinking the play is to redesign those three for dual type forms, but I've hit my deadline for today, so that will need to be a doodle for another day.