TvTropes and what they do to a person. I decided to try and use tropes for UlquiHime. I will also add some TatsuKira in another fic. :P
Trope: Lima and Stockholm Syndrome(s)
Rating: K+
Warning: I actually believe this is close to canon as it is not portrayed as romantic and also fits in with the story—I think.
The dead and the living shouldn't love.
It defied most laws and both the heartless demon and the kind-spirited human knew this.
Which was, perhaps, why neither of them dwelled on such things.
It wasn't possible for Orihime to deny she felt a little love for her captor. He protected her from the others, he kept her warm and well-fed, and he spoke with such cruel honesty that she never doubted he believed every word that fled his lips.
And Ulquiorra, in turn, respected his charge. She was strong for her kind and she watched him with glittering eyes, defying him while also accepting him. He knew the time would come where he would fight her and he was ready for it—Her loyalty towards her companions would eternally keep her from obeying him or Aizen-sama's wishes.
At night, she dreamt of him. They were rather innocent, actually. Him taking her back to the land of the living, him eating with her at her apartment, him telling her stories of his past. As time passed, however, his role began to change. The line between him and Kurosaki-kun began to blur as he continued to safeguard her and her dreams reflected this, having him dominate the role of protector.
At day, he thought of her. Her determination, her foolishness, her warmth. The heart did not exist, of that he was sure, yet she made him doubt. How could she cling to her friends so loyally when she had nothing left but her own memories to remember them by?
Time wore on and the relationship between them became something unknown.
Not love. Not hate.
Not even that of a guard and his responsibility.
Ulquiorra no longer defended her for his orders, but for her. Orihime no longer ate because of her will to live for her friends, but for her desire to please him.
Maybe Orihime wished to give him something because she knew she'd betray him.
And maybe Ulquiorra fought Ichigo so aggressively because he knew she would be taken.
He wished to understand her, to get why she had so much faith for the others. It became an obsession. What was the heart? He wanted to know. He needed to know. He needed to keep her with him and he needed her to leave.
And she became unable to see him as the villain, as the bad guy. In the dark of Hueco Mundo, he was her moon. Cold and unchanging in the dark world she had been taken to, but also always there and shedding just enough light for her to see. She wanted to reach out and touch him, teach him to become warm and soft, but couldn't because she wanted him to remain who he was—Whom she had grown to care for.
And then the time came for it to end.
Kurosaki-kun and the blood and the terrible wound. He had done that. He had been the monster.
Her shield for the boy. She was leaving him. She betrayed him.
All it had taken was one piece of trash.
All it had taken was the love of her life.
The trust between them—where had it come from in the first place?—dissolved.
It had been so fragile and so strange. A bond only a captor and his prisoner could have. One that acknowledged their opposition but also chained them to one another with something akin to camaraderie.
As he died, he realized what devotion was. What it meant to care for another creature.
And perhaps she finally learned what it was like to feel cold.
Their fingers almost brushed as he dissolved and he could see the tears she refused to shed. For him. She cared for him.
And he felt peaceful.
But Orihime wasn't sure what to feel as her detainer deteriorated. Sorrow, yes. One that was deep and painful but somehow calming. Calming and cold like the moon and the arrancar her love interest had killed.
A part of her left with him but she couldn't let her pain out. It was caged inside her, locked away as she healed Ishida.
But as the dust danced around her, softly resting on her hand for a moment before leaving, she felt her heart piece back together and looked to the dark sky.
He would remain with her.
Though it was not quite love, it was still a relationship that the dead and the living shouldn't have.
Yet Orihime could feel nothing but tranquility in this knowledge.