Please explain how you got your knight to ride the imp. I must see this for myself.
black belts aren't really good, but it's not like the game is so hard that it'll kill you to give one slot to one of them. My first game was without a fighter. I had a BB, Thief, WM, and RM. Also, I didn't figure out that my BB did more damage bare-handed until after Kraken. But when I finally did realize that, he became my best fighter. In an ending that seemingly only happens in the movies, I beat Chaos with every character dead except my BB, who had one HP left. So I can appreciate what a BB can do, yes. But overall there's no reason to take him except for variety.