Hinoto was wrong.
Kotori was right.
The future, the fate of the earth, was never "solid". It was never "decided", and it will remain fluid until the end of all time itself.
But as we can see, Hinoto was wrong. She foretold the end of the Dragons of Heaven, the death of Sorata and Kamui. She promised Arashi would be a Dragon of Earth. She promised a Tokyo underwater, a Japan wracked by disaster, and a world in flames. Hinoto "saw" this future, and they believed her. They believed her until they stopped believing her, because Hinoto "saw" wrong.
When Hinoto "saw", she determined exactly what she wanted to see. Who, what, where, when, how. She didn't see why. So she could never have foreseen the End.
The End, the Final Battle, is full of motivations and wishes only Fuuma can see. Each has a wish; to die, to live, to love. Motivations are perverted and wishes corrupted under Fuuma's gaze.
If one Kamui can, the other can too.
As Fuuma sees ink, Kamui (the KAMUI, not the "Kamui") sees brilliance and for the light he sees he dreams. And he reaches for it, this strange dream, and Hinoto is wrong. She sees this as suddenly as she loses control.
'Here, Hinoto,' says a voice that sounds suspiciously like Kanoe, just as Hinoto sees Kamui see, 'I'll grant this, just for you. It is what you want, is it not?' And the world spirals out of control, and wishes are flying like it's the day after tomorrow– that is to say, the day after the End, right?
Wrong.
The future is fluid and the Kamuis see it all at once. Kamui is looking straight up at Fuuma, the Holy Sword pointed straight at his chest, when it happens, and a moment passes where it is only Fuuma looking down at him, not "Kamui". (I can do it, he's there, it's Fuuma, let's go!)
That moment where Hinoto releases control, the moment Kanoe grants her, is all it takes. (Sorata thinks it's ironic that in the end, it was the Dragon of Earth's leader that saved the Dragon of Heaven, but he doesn't think about the End so much nowadays). Kamui's true wish is for wishes to be granted; after all, a twin star does nothing that the original can't Luckily, there's enough power between the two of them to grant 13 wishes.
Kakyou dies with a smile, and Hokuto greets her with a smile.
Satsuki and Beast die together, and it's interesting and logical at the end. She appreciates this, and smiles at Yuuto. He laughs at her.
Yuuto, wishless, unaware of Kanoe's death (which he wouldn't have really cared about anyway), dies in the battle. Karen killed him. He laughed. She gave him a somewhat puzzled look
Kusanagi's wish is easy to be granted no matter which way the battle falls. The war is over; he is free; the earth still burns, but he trusts Kamui to make it better. He knew Tohru, and he knows Kamui. It might not be perfect, but it will be better. Kamui's patches ought to last another, say, thousand years.
Yuzuriha and the new Inuki survive without a scratch. She wonders vaguely about this. Compared to everyone else, she has survived with almost no emotional or physical agony. She is forced to conclude that destiny is whimsical in that way, and she smiles up at Kusanagi and continues making cookies for Sorata. She never catches on.
Seichiiro has conflicting wishes within his soul, and knows it. He loves his wife, he really does. He just loves Karen with all the power destiny lends him. He is spared having to decide. His wife died in the Shibuya earthquake, another nameless casualty. He never mentioned it. He manages to let Karen know he loved her before his wounds take their toll at the battle's end. It's not a happy ending, but it's peaceful enough and he doesn't complain.
Karen mourns him for a year, then ceases because he'd want her happy. She formally adopts his daughter as soon as she can. The girl adores her. Karen adores the girl. It's family, and even with a broken heart she's never been so content. She visits Seichiiro's grave on Sundays and leaves him sunflowers.
Sorata dies for the woman he loves.
Or, rather, he tries to. If Hinoto can be wrong, apparently the Stargazer can be too. Luckily, Sorata's smart enough (or desperate enough) to figure out where Arashi's been hidden. Since Beast is dead and the other Angels are otherwise occupied, security is negligible and he retrieves her without problem. Ultimately, the future's fluidity has saved him. Arashi looks up at him with stormy, lidded eyes when he awakens her, and his heart stops for a moment to be afraid. Then she starts to cry, and he's still panicking but not so scared.
Arashi is just glad Sorata's still here with her, and that she still knows just who Sorata is. She makes him promise, through her initial tears, to never to leave her, to never die for her, and to never let her do something so stupid again. He agrees without hesitation. (It is, after all, not just dying for her. Sacrifice is different, and destiny calls still).
Subaru dies, simply enough. He meets Kotori and Kakyou, and Hokuto and Seishirou in the margin between life and death.
"I love you," is the first thing he says.
"Who're you addressing?" asks Kakyou.
"Them," he answers, waving a hand in the general direction of his sister and his lover.
"Good," says Seishirou easily, with a smile, "we love you too."
"Where to?" Hokuto wonders.
"Well, Subaru and I are off to reincarnation. I don't know about you guys," says Seishirou just as easily, grabbing Subaru's hand and pulling him along.
"Seishirou-saaaan!"
He leaves behind no Sakurazukamori. He killed himself when Kamui wouldn't notice. He knows Kamui will mourn, because the parallels seem stronger than ever. However, the parallels are also weaker than ever, because Fuuma's not Seishirou.
Fuuma's happy ending is bittersweet. So is Kamui's. Fuuma is Fuuma again, because the End has been postponed another thousand years to 2999. He has not been granted the reprieve to forget. He will live with all the people he's killed and all the damage he's done. Kamui, too, lives with his scars. He outlives all the other seals, and he never forgets a single one, nor ceases to regret that he couldn't save them all. However, his wish eternally strong; he and Fuuma stay in Tokyo and rebuild the shrine they both loved, and they do it together. Fuuma is Fuuma and Kamui is Kamui and life goes on, and so they live, they love, and ultimately they forgive.
So it goes, they know. A wish isn't all it's cracked up to be, and the world still spins.
And Hinoto was wrong.
Kamui thinks he'll never stop gloating.