I think martial arts should be individual based. I'd like to have my character do mixed martial arts, but I think it should be based on their zodiac. I think only some such as the tiger, ox, and maybe boar (Maybe dragon?) could do a form of martial arts. But other zodiacs could find their own niche. Like fencing for the snake, or ballet for rabbit. It doesn't even have to be physical (Such as singing or art), just a hobby that maybe makes that character feel closer to their zodiac symbol.