She should have been perfect.
She was the embodiment of Fire Nation elegance, a master of the softer skills that were considered so attractive in noble women. She managed the house with an ease that suggested an intelligence capable of much more. She could spend whole days sitting at the writing table, her back ever straight. She maneuvered the brush with the confidence and accuracy of a master warrior wielding a favored weapon. Her characters were as flawless as though produced by a printing press, and yet possessed of an artistry that belied her cold demeanor. She had a true eye for detail, and while she seemed to have a disdain for colored inks, her art had a simple charm that struggled mightily but vainly to give life to the dead pictures. If there were any areas where she had room to improve, it was in decoration and gardening. When she could be persuaded to resist her ennui, her lack of passion kept her from achieving any measure of success. Yet her new husband didn't mind.
What use had a murderer for growing plants and properly tied curtains"
What Piandao most appreciated about his young bride was her fighting skills. She naturally possessed every aptitude he had tried to hammer into his many students (to varying degrees of success), and more importantly, she had an unfailing confidence, or perhaps arrogance, in her abilities. Without even expending any effort, she made her knives into more than an extension of her body, but an extension of her very soul. Yet, what did it say about her soul that when it reached out, people bled"
What did it say about his own"
That's why he accepted her and tolerated her quiet resentment, her hatred for life, her disdain for all his most sacred beliefs. He pretended to love her, even though he most definitely had a choice in the matter, because it seemed appropriate. Although her heart continued to beat, breath filled her lungs, and blood flowed slowly but surely through her veins, she acted like one already dead.
Everybody he had ever reached out to was dead. His wife should be no different. She was a constant reminder to him, that skills were not enough, that victory was not a goal unto itself. Whenever he looked on her poisonous beauty, he internally recoiled, and his resolution was further reinforced, to find someone worthy to pass his teachings to. Someone who would use them for life. Someone with the humility to avoid becoming a killer, but rather a guardian, even if it still demanded the taking of life.
Someone who might never come.