How can I get the whitetreehollow key in Black 2?

Question

I want to switch to white forest in my black 2 game because I have beaten black tower and want to see the white tree hollow but I'm not sure how to get the key to change the city.

Answer 1

You must use Unova Link on the title screen to receive a White Treehollow key from a person who has White 2 and has it.

Source: Experience