Torn, slit, and punctured, they piled in mountains and plains that stretched across the void. They had no pulse or color. The newborn heart didn't know what fell its kind, nor did that matter now. What started as whimpers that reached the far corners of this realm twisted into wails billowing in the sea of the dead. Someone was hurting.
The little one hurried.
Over the strewn corpses peered a living heart. It was the one wailing. The reason became apparent.
"Stop!"
The other was all but cleaved in two, along the line that divided its light and darkness, milk white and tar black. A key-shaped blade protruded from its lower appendage, sawing through the dwindling number of filaments that kept the sagging halves attached.
"I said quit it!" The little one grasped the grip of the enchanted sword, heaved, and was yanked along. To the beat of cracks and rips, over the sizzle of the other heart's tears, the weapon with no mouth to and froed in the shape of a sneer, as if laughing. The little one wouldn't let go. It couldn't.
As if hearing their owner's wish and possessing a will of their own, strands of yellow seeped out of him unbidden and wove themselves into the halves. More filled the break, slowly mending the other heart. The little one swayed. It was giving its life away. It felt a tinge of regret from the burden it would become to its future soul and body, but there was nothing else it could do. The other heart needed it more.
So, when the sword tore through the bottom, pieces the little one had forfeited held the halves together.
The sword slashed upward, slicing through them.
One set of screams split into two.
"No!"
A tempest erupted in the rift between them. Visible winds surrounded the one of pure darkness as the eye of the storm. The gale swept through the little heart. It failed to save the two, and now it doomed its unknowing host to a life as a cripple for nothing. The little one choked. These thoughts weren't its own. There was so much contempt. It couldn't hold onto the weeping light half any longer and was swept away.
But there, inside the dark half, amid the swirling negativity was a speck of light—the little one's light. It couldn't save them, but maybe, that was enough.
Author's Notes
Fair warning: I'm a very slow writer.
KH AU reboot where Sora's heart comes to the rescue earlier than in canon. He fails to heal Ventus's heart but manages to leave a bit of light inside Vanitas.