What can you do in pokemon black after elite four?

Answer 1

You can do tons of things after defeating the Elite Four. Try entering some Pokemon Contests, or battling in the Battle Tower. Perhaps you'd like to continue catching Pokemon, since there are soooo many of them to be had now. The game doesn't end with the Elite Four! Remember that!

Answer 2

You can travel through the eastern half off Unova past Opelucid City. Also you'll encounter wild pokemon from previous gens. You can also challenge the Elite 4 a second time in which they'll be MUCH harder and you'll get to face the Champion this time around.