So, my idea for the antagonist. He is the master of his dojo and has several badass "instructors" under him, who will be the ones participating in the tournament. Personality wise, I'd say sexist brute works. Make him abusive to his students, especially the weaker ones. He extorts businesses for what they have, but moves on to another town once the authorities start putting pressure on him. He uses his dojo both to recruit new thugs and to launder his extortion money. He could have a son and a daughter, but gives his son preferential treatment since he is naturally stronger and better suited to his style of swordsmanship. His daughter secretly enters the tournament to prove herself to her father. Could be a bit of drama there as well; will she be reformed, or fall in with her corrupt father and brother? As for his name, how about Ryuuto Tajima?