Homura was thrown violently to the ground for what may have been the thousandth time. The pain in her 'body' was nothing compared to the pure agony in the deepest parts of her being as her soul gem was corrupted far past the capability of any grief seed to heal. She made no attempt to get up this time.
She rarely reached this point. Most timelines, she never got to take a shot at fighting this monster, the ultimate witch. There were too many other things that could go wrong first. When she actually managed to get here, those were the moments of greatest risk and greatest reward. Everything she'd been attempting to achieve was within reach if she could just win one last fight. But if she lost...each and every time she lost and escaped with her soul gem intact felt like a miracle, luckier than winning the lottery ten times in a row. It seemed her luck had finally run out.
Despair was the doom of every Puella Magi. Homura had escaped its insidious grasp thus far due to her unique power, knowing that no matter what horrible things happen, she could erase it all and try again, rinse and repeat as many times as it took to get it right, as long as she survived. That nearly indestructable hope made her the most powerful magical girl in existence. An ordinary witch, even ten or twenty ordinary witches, posed no threat to her.
Walpurgisnacht was no ordinary witch.
It wasn't enough that the monstrosity was nearly invulnerable, shrugging off her strongest attacks like a bull blowing a gnat out of its face. It wasn't enough that it could in turn obliterate her with the least of its own attacks. If that were all, Homura would never doubt her eventual victory.
The problem was that it was intelligent in a way that no witch should ever be. It could think, anticipate, strategize. Regardless of her time stopping power, it was ten steps ahead of her at every turn. She hadn't known it until this timeline, but she came to realize over the course of the fight that this wasn't a fight at all. This was a child pushing its food around the plate out of boredom. This was a cat knocking a helpless mouse from paw to paw. This was a tiger twitching its tail, just waiting for the lone, sickly zebra to make the first move.
It was toying with her.
Once she understood that, despair was inevitable. The ending where she managed to slay the beast and rescue the damsel couldn't be found no matter how many retries she got, because it didn't exist. Death was inevitable.
It did, however, raise one last question, which Homura considered as her soul gem made the last few swirls from purple to black. Why? Witches didn't play with magical girls. They executed them at the first opportunity. Even if this one was freakishly intelligent, what could it possibly gain from torturing her like this?
Realization hit her, the final blow on her degrading psyche. It knew. It understood the relationship between Puella Magi and witches, in a way that other witches didn't have the sentience to comprehend.
It didn't want to kill her. She was lying on the ground, helpless and defeated. The fight, if a fight ever it was, was over. The was only one reason left not to finish her off.
It wanted her to turn.
Homura had nothing left to live for, so the possibility of dying didn't bother her. In this particular timeline she'd managed to prevent Madoka from contracting, but she couldn't get her out of the city. Walpugisnacht would kill her last reason for living after destroying her. There was only one possible fate worse than that. If she became a witch and killed Madoka herself. The last shred of self left in her would do anything to prevent that.
She was turning. Too late to change that. Only one thing she could think of to eliminate that hideous circumstance from being a possibility.
There was an advantage in having crossed the line of no return. A Puella Magi could never unleash her full power with the threat of destroying herself hanging over her, but now Homura had that option. Summoning every ounce of power within herself, reaching into depths she had never dared touch, she exceeded her limitations with the most powerful spell ever cast. No matter the cost, Madoka would be safe from her own hand at least. Her specialty, time magic, would make it so. She flung her doomed existence back in time.
She just had to go back far enough her witch never encountered Madoka. As far as she knew, a witch would never die of old age. It had to be killed by a magical girl. She was buying time for the magical girls of the world to kill her before Madoka was born. How far was far enough? Fifty years? No. Too risky. One hundred? Still no. She needed certainty. A thousand? Closer. Two. Three. Five. Ten. She kept going, past the birth of Mankind, past the dinosaurs, as far as she could, as far as her strength could take her.
When her body finally came to a rest from its trip through time, she lay on a barren earth, the only living thing, if living she was, on the planet.
And then the recoil hit her.
Pain beyond pain, beyond imagination. It didn't come in waves, it was one extended neverending experience, dwarfing her ability to endure, or even comprehend and experience. And it wasn't tied to her body, it was her soul going through an ordeal so much worse than destruction. There was nothing worth this. Not love, not beauty, not Madoka herself was worth this. Her soul was twisted and transformed into something new, something that defied explanation and reason, something beyond the ken of the incubators, whose inane meddling had inadvertently caused this turn of events.
The pain lasted a mere moment, a moment that seemed to stretch into eternity, but it did end, and when it ended, the thing that was left knew things that no other being in existence knew, things the incubators thought they knew, things that other witches would know if they had anything like a mind left within them, but they did not, so knowledge was reserved for one alone.
The incubators thought that witches were beings of despair, that Puella Magi and witches, the relationship between them, the transformation process and the energy generated by it, was about the balance of hope and despair. It was not. That's the kind of misconception that could only come from a species incapable of emotion.
That a witch was formed when despair overwhelmed a Puella Magi, that was true enough. Despair is truly destructive, capable of utterly consuming a being. What the rat species did not realize is that despair is self-contained. It spreads like cancer, eating away at a single being until nothing is left but an empty husk and even the despair itself is consumed, not like a virus, jumping from one host to another, ever living and always getting stronger. Despair is stagnant. It has no power to move, to motivate. There is no energy to be gained from it. Despair is what destroys a magical girl, but it is gone once it does. The thing that is left feels none. A witch is not a being composed of despair.
The thing that was once Akemi Homura used the final moments in its old body to grin, a grin that would leave Sadako screaming in terror and running for whatever passed for her life, as it was filled to overflowing with the true essence of every witch, the only thing a witch is capable of feeling, a feeling that Akemi Homura had ironically been all too familiar with. If any other being with auditory perception had been around, they would have heard a distorted singsong voice say, "Hello, darkness, my old friend..."
And then the old body exploded in a surge of power, leaving behind it a being formed entirely of one substance.
Hate.