Opelucid City is where you will get your final Gym Badge, the Legend Badge. In Pokémon Black, the Opelucid City looks very futuristic, but in Pokémon White, it looks much more old-fashioned.
Talking with Drayden and Iris
When you get to Opelucid City, you will see Alder. He will take you over to a crowd of people who are listening to Ghetsis. He is telling everybody that N has revived the legendary dragon, which makes him the true hero, and he urges everyone to release their pokémon.
After Ghetsis leaves, you and Alder talk to Drayden and Iris. Alder tells them that he will go back to the Pokémon League to fight N.
Iris has you follow her to Drayden's house. The two of them tell you about the legendary dragons. They started out as one dragon, but the twin brothers who trained it wanted to use its power differently, so the dragon became Reshiram and Zekrom. Reshiram represents truth, and Zekrom represents ideals. The two dragons fought so fiercely that they destroyed Unova long ago. Clearly N wants you to catch the other dragon and fight with him, but Drayden and Iris fear that this could destroy Unova all over again.
In the Battle House, you can battle once per day against Ace Trainer Eileen and Ace Trainer Lou. Eileen has an L39 Mienfoo, Elgyem, and Pawniard. Lou has an L39 Simisage, Simipour, and Simisear.