lol, if yous really want the dif forms, trade a rotom from D/P/P to SS/HG. you know that useless Silph Co. in Saphron City? Remember the elevator that doesnt work? Well have rotom in your party and the elevator will mysteriously work, and it will lead to the room with the fridge, lawnmower, fan, and microwave (i think, maybe oven.. idk) and rotom can enter them and change form (rotom might have to be first pokémon in party for this to work.) So yea dats how you get the changing rotom in SS/HG.
Yes I am a pervert. Yes I am better than you. Now get out of my sight.