The Nature Reserve is one of the greatest places to go in Black 2 White 2. It is the home to the amazing Shiny Haxorus!!! I just have one question. In order to gain access to it, you need to have seen all of the Black 2 White 2 pokedex. But one pokedex entry (No. 299 I believe) is that of Meloetta. Is there someone that will show me a pic of Meloetta or something so that I can gain access to the Nature Reserve? Or do I just have to wait for the Event to come out? (I am wondering the same thing about Keldeo because I do not have one and I cannot seem to get one via trade.)
>After you've seen all of the Pokemon in the Unova Dex (297, not counting Victini, Keldeo, Meloetta, or Genesect), you'll be able to receive the License from Professor Juniper in Nuvema Town.
You don't need to see it.
Source
As far as I know, Meloetta won't count. Say, if you have an event Pokemon and only an event Pokemon missing in your National Dex, when it's evaluated, it basically counts as if you got them all.