How to obtain Tornadus, Thundurus and Landorus?

Question

A simple question I want to know the answer to.
Doesn't everyone?

Answer 1

In Black and White 2, you can get them by trading from Black or White, or using the Dream Radar, which is an app on the eShop that costs $2.99.

Source: Experience

Comments

(you can get them in the α,β and γ Eureka Extensions. http://bulbapedia.bulbagarden.net/wiki/Pok%C3%A9mon_Dream_Radar#Extensions)