According to Bulbapedia, there are 4 Pokemon with the ability Wonder Skin.
Sigilyph's Slot 1 ability is Wonder Skin, so you do not need Dream World access for this.
However, with Venomoth, Skitty, and Delcatty, for whom Wonder Skin is a hidden ability, this is more difficult.
In Pokemon Black 2/White 2, there are only a few sources of Pokemon with hidden abilities that do not involve connectivity to the 3DS (Dream Radar), or the Nintendo servers (Wi-Fi/Global Link Event, Dream World).
For future reference, in case another Dream World ability catches your eye, you can obtain these Pokemon through:
Venonat can be found in the Hidden Grotto on Route 3 (Pond). Evolving Venonat will give you a Venomoth with Wonder Skin.
However, neither Skitty nor Delcatty can be found in Hidden Grottoes, nor do the in-game events contain their Dream World variants (Such events include the recurring Braviary on Route 4, and Musharna in the Dreamyard). N's Pokemon can only be caught if you performed a memory link with a previous game (difficult to do without using the physical White 2), but it appears that N did not have Skitty nor Delcatty.
The last legal/legitimate option in this case would be to breed a fresh Skitty. However, since the Pokemon cannot be obtained any other ways, this is a bit of a Catch 22. But if you would like some peace of mind about using "Genetically Modified Pokemon", you can utilize save editing software to give yourself a temporary female Dream World variant to breed, and then release it afterwards, keeping the eggs. Because most Dream World Pokemon arrive in the Entralink at Lv 10, hatching a Pokemon at a low level would probably feel more legitimate.
Save restoration through the link given above by Theodore is also a good idea. I would suggest that perhaps you enable Memory Link on your physical copy after dumping your save file onto it, to allow for N's Pokemon to be caught when you play on your emulator again.
Finally, a full list of Dream World variants and their in-game locations can be found here.
Yes you can. However you need some special hardware.
First you need a Flashcart. A flash cart is an special cartridge which allows the use of homebrew in the DS. Homebrew software is software developed by the community to be used on certain device or environment. This homebrew usually comes in the form of roms or similar.
With that said, you can use such a Flashcart to load a .rom into it, and then use your DS with that cartridge to launch the .rom. Now given that you already have a save file you want to transfer, you need to copy the save file to the Flashcart too, these files are usually placed besides the rom, by the respective emulator.
Now, following this process you cannot transfer the pokemon between your Flashcart and the X and Y games, because of some security measures implemented by Nintendo. So you need to transfer them to a previous generation game first. Which is great given that you do have the Black cartridge.
So, to transfer the pokemon between the two Black versions you need two DS with the respective cartridges, and use the Union Room to transfer the pokemon.
Once you got your pokemon into the real cartridge, you can transfer them to X and Y using Pokemon Bank.
Note: I have not done the process myself, but some time ago, I was thinking about getting X and Y, and looked up about the transfer possibilities. And i read some tutorials explaining what I stated above.
Best Answer
I had the same problem with my RetroPie cabinet. To solve this I devised a joystick system with an integrated credit counter. The system disables the insert coin buttons unless credits are available and includes a little challenge that must be won in order to obtain them. The challenge is the Simon Says electronic game created by Ralph Baer and Howard J. Morrison in 1978. As in the original Simon game there are several skill levels. The number of credits obtained when the game is won will depend on the selected skill level. You can see the project at hackster.io and github.com. You can also see a video demo at youtu.be.