So I bought Pokemon black for nostalgia and I know you can trade from black 2 and white 2 to black and white. Thing is I have a moxie salamence in my black 2 I want to trade to black, but I don't know, because maybe it's not supposed to have that ability in that particular game. If I trade it there will it be irreversibly changed to intimidate? Does that apply to others?
It will not lose Moxie. Moxie was an ability in that game (reference Krookadile) And it will still keep that ability for that pkmn as long as it did exist. Maybe not for that pkmn but as long as it existed you will be fine to run around terrorizing gym leaders with your Moxie Salamence good luck, hope I helped, God have mercy.