Sorry, the only DW Landorus I have is technically from PokeRadar, but in reality my friend used an external device to trick the game into thinking I'd connected to Dream Radar, so it "recieved" it and gave me the go ahead to get the Reflecting Mirror. Also, that's on my Acekard; I do not use that game for any trading/RNGing purposes, just to clarify. So, I don't think I can help you there.
lol what? reflecting mirror is a key item and cannot be traded. also the therian forms do not exist in black 1 and white 1. also to get the mirror you have to take your dream radar landorus to the abundant shine.