I've tried making him use Rain Dance in Gen 7 Ubers and Gen 7 Doubles OU to test out a strat I'm working on, but the move, instead of being blue, is faded out white and unusable. I may need to trouble shoot this in different formats but I was wondering if anyone has encountered a similar problem before.
You know what, my Toxicroak did have an assault vest after I checked to make sure, I feel dumb now, but thanks so much for helping. commented 4 minutes ago by Jay_Karma77
Don't worry about it too much, I've made that mistake more times then I remember. As you know, while holding an Assault Vest, you gain 1.5x Sp. Def, though as a result, you are unable to use any status moves. Showdown makes these unusable status moves appear faded out, which is to show that the move is unusable. As a result, your Toxicroak couldn't use Rain Dance.
Source: Experience