In Pokémon White Version, when the player first arrives in Opelucid City from Humilau City, they will have to battle Cheren and Bianca.
Afterwards, Drayden gives the player the Legend Badge and explains a Pokémon League is being built in Unova. The Pokémon Trainers of Unova begin building an army of Pokémon to prepare for this.
The player must defeat the Elite Four and Ghetsis in Pokémon White to fully establish Unova’s independence from neighboring countries. N captures Reshiram/Zekrom and plans to use it as a weapon while attempting to rule Unova, or while waiting for the Pokémon League to be built.
Ghetsis reveals his plans to rule Unova have failed, so he turns N in Pokémon Black Version 2 back into a Pokémon. The Pokémon League is then constructed in Pokémon Black Version 2. Cheren becomes the new Pokémon Champion, while N is turned back into a Pokémon by Ghetsis. Drayden gives the player the Legend Badge, which is able to be transferred into Pokémon Black Version 2.