I'm not sure if its a pokemon unbound thing (which uses CFRU) or not, but I noticed that with moves like aqua ring, if you swapped out of ditto after using it, it permanently gets rid of imposter, and is no longer affected by quickpowder. I'm not sure of any other moves that do it, but I noticed it with aqua ring. Highly likely its a CFRU thing though.
I'm not sure if its a pokemon unbound thing (which uses CFRU) or not, but I noticed that with moves like aqua ring, if you swapped out of ditto after using it, it permanently gets rid of imposter, and is no longer affected by quickpowder. I'm not sure of any other moves that do it, but I noticed it with aqua ring. Highly likely its a CFRU thing though.