He should use a drill....THE DRILL THAT SHALL PIERCE THE HEAVENS!!....no seriously a drill like weapon would actually be cool, like a double-sided drill lance thing. I think they can do something interesting in gameplay with that.
I don't really see the need to mess with the formula. Swords are fine. Save the bizarre and flashy weapons for the party members.
Have a main character be an Iaijutsu practitioner. Iaido is a martial art based on the combat style, providing a real world possibility for proficiency, and the quick draw style allows flashy attacks while keeping the sword.
Stereotypical? Sure. But it's still a cool thing to watch.