Black

Black is a young man who aspires to be the Champion of the Unova Pokémon League. He has been dreaming of this since childhood, nine years to be exact. However, these dreams fill his head to the point where he cannot think about anything else and any attempts to cause him to pass out from mental exhaustion. With his Munna, Black can have him eat his dreams, which he refers to turning his mind from "blank white" to "solid black". Doing this allows him to think much more clearly, become smarter, and improve perception. Also, when he does this, he apparently sees in hexagons. Because of his dreams causing him to forget about other things, Black has the tendency to do things without considering the consequences of his actions and their effects on other people. As the series goes on, Black slowly begins to consider the feelings of others and even manages to be able to think about other things for brief periods of time. He has been described as "hot blooded" by several characters due to his loud nature and tendency to do things on his own. He doesn't understand show business like White does and many aspects of it surprise him, such as Gigi and Tep getting to stay in a hotel room while he and White have to camp out. He is very familiar with libraries and went there frequently as a child, allowing him to complete Lenora's Gym puzzle very quickly, setting a new record in the process. Black's tendency to dream also causes him to miss the things happening around him, such as when he completely forgot his promise with his friends Cheren and Bianca once he received the package holding the Pokémon and Pokédexes they were going to receive. After he defeated N and Ghetsis, Ghetsis borrowed Colress's Beheeyem to push Black while Reshiram is transforming and Black became one with the light stone. (Source: Bulbapedia)