If the Pokemon is findable only in Black and not in Black 2, you need to put "Pokemon Black" in the "Origin" form in the '1st page, Poke Transfer Lab at the Met Page, Encounter must be at Egg/Pal Park etc, level can be any, DO NOT mark fateful encounter or egg.
If you want it to be at lvl 100, then the level met must be 100 as well.
If the nickname isnt checked, it will come out ARCEUS, like all pokes in game.