Noh was a promising young martial artist, once upon a time. He studied hard to develop himself, not just as a fighter, but as a person. To fight properly demanded honor, discipline, and sincerity. It was just as much a way of life as it was a means of protecting himself. In this, he did well, for he had considerable natural ability and eagerness to learn whatever he could. However, as he grew older and his peers slowly eclipsed him, Noh found himself unable to embrace the whole of his philosophy. He strayed from his path and found that he had lost what part of him wished to return to it. Or, perhaps, that part had never existed. Years of training became suddenly devoid of meaning and Noh became empty. Without this part of himself he would never be able to move forward. His only choice would be to find his raison d'etre, his reason to fight.
Cowardice
Noh cannot give himself properly to a fight, and when forced into such a situation he becomes painfully aware of the emptiness. Without his reason, he avoids committing himself. This goes far beyond what one could call an even temper.
Serenity
To create peace and order is the ultimate form of self expression. To give each thought and action in the world purpose, and to seek this purpose unerringly is the right of all living things. These are the things one can control, and in controlling them one creates virtue within themselves.