Castform is a gimmicky pokemon, who needs to be used on a Weather Condition. Under sun, Castform will became Fire, under rain, he will became water, and under Hail, he will become Ice. But, that’s it! How about a version of Castform for Sandstorm, and especially the New Moon, which you added on the game. How about that?
Castform would became a Rock Type under Sandstorm (and that would massively boost him, because 1,5x Spdef on the Sand), and the Weather Ball, obviously would became a Rock Type (Stab).
And for New Moon, Castform would became a Dark Type, and the Weather Ball, would became a Dark Type (STAB).
What do you think, guys? Give Castform some love! <3