[One-shot] Being immortal doesn't necessarily mean you can't die. Rated T just in case.
"It looks like immortality isn't what it's cracked up to be is it?" he asked while lying in her arms, his entire body covered in blood, both his and others.
"Quiet you fool!" she hissed. "We can still heal you, it's not too late." She continued in a whimpering voice.
"It's alright Kitty, it's far too late." He said, a dim smile protruding from his busted lips. "I let the darkness run free for too long. I've lost too much of my strength to hold it back now. It will consume me."
"I said to be quiet!" she once again hissed.
"I have a request. Will you listen to it?" he asked her.
"What?" she asked, tears beginning to stream down her eyes, hoping her thought won't come true.
"Before the darkness consumes me, can you end my life? I want die while I'm still with you." He asked her, his throat dry and his voice raspy.
"How could you ask me such a thing? To ask a master to end her disciples life; to ask a woman to…" she stopped short, small sobs escaping from her throat, tears cascading down her cheeks onto his forehead.
"You're the only one who can. Besides, if anything should kill me, I'd prefer it be you." He answered. He tried to smile again but the blood in his throat forced its way out leading to a violent cough.
"I c-cant… I could never… k-k-k…" her sobs worsened and her voice refused to complete the sentence.
"To think I would see the day that the Dark Evangel cries. This truly is a twisted world." He laughed, his voice hoarse from the coughing. "Eva, do you regret making me your disciple?"
She stood silent for a few seconds, collecting her thoughts and drying her tears. "You were foolish, idiotic and reckless. You tried to keep everything to yourself and caused endless trouble to those around you. The worst disciple I ever had!" She spat out, her lips trembling.
"Haha, I was pretty lousy wasn't I?" he said mockingly, a slight smile stretching across his lips.
"But I never regretted it, not for a single second. Not for anything that's happened since. As disgusting as this sounds, you gave meaning to my life." She said tears once again threatening to spill from her eyes.
"Thank you Eva." He smiled. "I would love to stay and chat, but it's almost here; will you do it?"
"Y-yeah…" she answered, with hesitation still in her heart. "I won't let anything else take you away from me. Only I have that right."
"Then lets end this." He said, closing his eyes.
"Ensis Exsequens…" she enchanted, the blade of pure magical energy extended from her right hand. "Goodbye, Negi…"
As the blade came into his heart, Negi told her his final words. "Evangeline Athanasia Katherine McDowell, I will always love you, regardless of what happens. Promise me you'll live happily."
"Of course I will!" she choked out as she brought her lips to his, the taste of blood filled her mouth.
Without a word, he raised his hand and patted her head, a large, content smile on his face.
Then, his hand fell and there was nothing but silence for a short time.
He would never again open his eyes, he would never again smile at her, he would never again hold her close, and she would never again feel the touch of his warm lips.
The silence was ended, a lone girl sobbing, crying, holding him close, and sobbing into his chest even as his body gradually lost its heat. She would there, alone, for several more hours, regretting his death.
And the silence returned. The girl no longer sobbed, she no longer cried, she no longer held his body close to hers. She had made up her mind.
She would live happily, just as she had promised him, but all of that came afterwards.