Kuroko listened to the oracle's words, her predictions, her vivid details on the small red string that tied Kuroko to Akane. It wasn't something that the gods had just decided. It wasn't a silly little string that connected them together for the short time Akane would be alive; rather it was strong like a chain, put purer that tied their souls together forever. He had been surprised in the beginning, but couldn't seem to forget the way he was captivated when he had first meant Akane. Kuroko from that moment had no doubts that he was meant to be there for Akane for the rest of eternity as their souls came to find new bodies and new lives.
He could image, watching over Akane for the rest of his life. Watching her grow older and using his magic to age his body to match hers. Kuroko could imagine showing her off to his clan; holding her hand as she meant so many more demons that were far more loud and outgoing than himself. Though, Kuroko couldn't help but also imagine what kind of reincarnations that Akane would undergo. If he would have to reintroduce himself to her soul again or what he would have to do. Though Kuroko didn't think he'd mind either way as long as that soul still carried Akane's carefree spirit with it.
The oracle had also predicted that eventually there would be a marriage or union between the two beyond that of friendship. Kuroko was unsure of any romantic feelings toward Akane. He could understand that over time, he could fall in love with her. He could see their friendship expanding to the point where they wanted something more than the simple times where they held hands for safety and for comfort.
As the oracle continued she spoke of how blue would meet red and gold which would create something far stronger than the Akashi family line could stand. That the Akashi line would no longer be as pure and as great as before. Kuroko would become the one thing that threatened the Akashi family and would ultimately taint it.
It was after that moment that Toru had lost it and lunged to attack Kuroko. Akane had looked at Kuroko in fear and had told him to run as she held Toru back. Kuroko understood that he could use his powers against Toru; that he could kill the boy where he stood and that he could give into his demonic nature and enjoy taking the boy's life. However, he could only think of the pain that it would cause Akane, who was now walking the line between choosing her family and choosing the demon she had meant a few weeks prior. Kuroko observed how she held onto her brother one last time, her golden eyes filled with sadness as tears fell down her cheek. Kuroko knew he'd never be able to kill Toru if it meant being the reason that Akane's eyes darkened with a permeant sadness. So despite the shame he knows Aomine would have felt for him, for running from a pathetic human child, Kuroko chose to run. He chose to rely in the future that the oracle had told him about and had promised himself he would never kill any of Akane's kin.
Akane watched as her father and brother glared at her. It had been weeks since the last time she seen Kurou; since she had seen the oracle and her brother's dagger. Toru had hit her after Kurou had ran. She was a traitor to their family line; she chose a demon, something worse than her choosing to defile the family's name with another human.
She listened to them discuss her punishment. She listened to how she'd be locked away in the Akashi manor and would never be allowed to leave the home and would be treated as the traitor she was. They were too ashamed to let her leave and too proud to acknowledge that their daughter betrayed them. She listened to them debate about Kurou-kun's fate and the role of the Akashi men to rid of him.
She listened to them fight about whether they should kill him- which they had finally agreed was best for the family and the world, to rid the world of another demon- and how. Akane heard rumors of her being used as bait and others of them going out on hunts to find Kurou. For years she heard of their trips, how this was the only task that any Akashi had ever failed and that the demon was despicable, using small, dirty tricks against them to escape and to disappear for months at a time.
Akane sat in her home for the rest of her life, listening to her brother and father discuss the Akashi duty of catching the fated demon that would ruin the bloodline. She watched the shadow from her window, that walked on the edge of the forest, that left a small rose on her windowsill every morning, that always protected her and loved her from afar. And Akane Akashi watched as her father and her brother created the tradition to hunt and kill the disappearing demon to keep the bloodline clean.