Sadness. 
Many authors had try to analyze it. Artists tried to depict it, and musicians tried to make you feel it. All of their efforts have failed in one way or another. Sadness is a complex thing, taking on many different forms, and felt in many different variations. Anyone who had ever tried to analyze, depict, or make you feel it had only focused on one aspect. If you asked the man, he would say that was what angered him most about her. She thought of herself as simple and one dimensional. He, on the other hand, saw every side of her: Every shed tear, every shade of blue, and every word left unsaid. How could she ever water herself down like that? It only made him love her more. 

There is the simple sadness. The kind where one might shed a tear over a beloved book series or TV show coming to an end. This was the sadness that she let people see from time to time. You could see it in her eyes, when they traded in their mischievous glimmer for a look of exhaustion. Her tone of voice would become quiet, and the way that she held herself suggested that if you dared to ask, she might just spill her thoughts. Because the truth was, she did need a release every once in a while. 

Then there is the sort of sadness that creeps up on you and feels like it lingers there for a lifetime. She only allows those closest to her to see it. She'll stare off into space, isolate herself, avoid eye contact, and never say any more than three words at a time. 
Last, but not least, there is an overwhelming sort of sadness - his personal favorite. During this time, her cheeks would be flushed; her eyes tinged with red. Her face would be soaked where she had allowed the salty tears to flow freely. Her lips would be a few shades darker from where she had bitten them - a weak attempt at trying to regain self control. Nimble fingers would reach for her throat, to play with the charm on her necklace - a nervous habit. Her hair would fall wildly in an attempt to hide her face. It was times like these when she became angry and bitter. He had never seen someone show so much raw and pure emotion then when she did during these times. This was when he found her to be absolutely breathtaking. 

When she got this way, she would say whatever was on her mind. There was many a time where she had claimed to have felt nothing but numbness; times where she begged to be left alone, and he refused to leave her. There were times where they stayed up into the earliest hours of the morning. She would talk, and he would listen. He knew the deepest, darkest, most hidden parts of her soul. Oh, how he loved the darkness within her - how it completely and utterly fascinated him. 

There had also been times where he had wrapped her in a fierce hug, as if her could shield her from all the bad things in the world. Time where he buried his face in the hair at the nape of her neck. He would listen to the steady sound of her breathing, and during the times where she said she didn't know if she was dead or alive - that sometimes she thought of a nightmare that she might one day wake from - he would take her hand in his and place it over her beating heart. A reminder that she was, indeed, alive.

Sure, he loved the moments where she let herself cry freely, but he also cherished the moments when she really smiled, the smiles she didn't fake - the ones where her eyes lit up. The sound of her laugh brought him joy unlike which he had ever known. 

Many people would tell you that happiness countered anger, and they would be right, for happiness countered lots of things. But in their case, sadness countered anger. Though her soul was set in darkness, she was his guiding light. She needed him, and in some strange way, her needed her, too. He needed her there to calm him during his rages, to let him know everything was going to be alright - even if she didn't believe it herself. To tell him that he hadn't become the monster he believed himself to be. 

She was his, and he, hers.