I was thinking, since no one really knows BHK's actual name, then maybe he doesn't have one. He is the other side of Sora's heart and shall be nameless. Maybe, just maybe he develops a name throughout the game or someone gives him a name. Whatever his name is, it has to be something that suits him or something he is experiencing. For instance the names Kairi and Riku are synonyms in Japanese for the word "separation." In reality, they were separated throughout most of the first game. It's just a theory. I think it's a good one.