Sebastian heard his sister's scream from three floors below.
"I'd been waiting until the 'opportune moment' to do this, but I'm afraid I have to kill you now instead." he drawled, and held his seraph blade to his chest, point outward. He spoke the weapon's name, and it lit up as it extended.
Then he bolted for the staircase.
Sebastian raced up the spiraled steps. If he had needed the way to be lit, then the seraph blade he was clutching would've given the glow that human eyes required.
He reached the top as Clary collided with the wall behind her, as the demon reared up.
Sebastian leaped forward and swung his blade down on the demon. He landed, and straightened. He gazed indifferently at the vanishing monster and it's black blood running over the cobblestone. He surveyed the courtyard, silver-and-onyx eyes searching.
He saw Clary. Sebastian took in the image of his sister: hair tangled, pale skin, and blood-soaked. A ring of puncture wounds ran their way around her narrow wrist. She had shadows beneath her eyes, which were wide with astonishment.
"Get away from me, Sebastian." she hissed.
Choosing to ignore her demand, he calmly said, "Your arm."
She looked down at her right hand, as if just noticing it for the first time. The round marks were leaking out a blue-black color into her skin.
"Clary." The girl's eyes drifted back to his black ones. They were unfocused.
"Those suckers, did you touch them? Clary, listen to me." Sebastian growled as her eyes darted around, trying to focus on something.
"They're filled with deadly poison. What the hell were you thinking, Clarissa?" he used her true name, "Dammit, what gave you the idea to fight off six Dahak demons with an ornamental axe-"
"Poison." Clary murmured, her head lolling, "So I guess you didn't save my life after all, did you?" The short laugh she gave was ironic, sarcastic- or maybe even triumphant.
"Clarissa!"
Her hand twitched and spasmed, the axe clattering to the ground. She fell against the wall, slipping to the floor.
Sebastian walked to her, hesitantly. He had seen so many deaths, and caused a majority of them. But for some incomprehensible reason, he didn't want to see his sister die. Not without his hand wielding the blade, without the triumph.
He knelt beside her, laying his hand on her cheek. The emotionless black stones that were his eyes were glistening with water. "Clarissa."
"Jonathan." Her voice shuddered and cracked, "Jonathan, help me."
He gathered her head in his lap, and stroked her hair as if she were a small child.
He felt a tugging sensation behind his eyebrows, and didn't know what to make of it. He felt a crushing sense of failure, the defeat of an attempt gone awry. It wasn't unlike what he had felt awakening to fine the creature that he preferred to his mother gone. But...
This was different. Like a stone being cleaved apart. It must've been because... because they were the last Morgensterns. They were family.
Clary drew a shaky breath, "Jace..." She let it out.
"No." Sebastian muttered. He didn't lose it like people did in movies. He didn't fall apart. He just cradled his dead sister's head in his lap, as something pricked him between his eyes and at his jawline.
Sebastian's pale, thin, artist's fingers made contact with Clary's eyelids, and drew them shut.
A drop of water splashed onto her nose, and a tiny fragment of the demon in Jonathan Christopher Morgenstern was singed away.
"Clarissa Adele Morgenstern. Atque in pepetuum, soror, ave atque vale."