Asunaro City.
Currently under attack by a lone Puella Magi.
A lone girl brought this once proud city lying on the ground, gasping in vain for its final breaths of air. White hair, surrounded by hundreds upon hundreds spherical marbles of materialized grief. She carried a massive warhammer that could destroy concrete with a simple tap.
Asunaro City had a protective barrier that wiped away a Puella Magi's knowledge and ability to perceive the incubator Kyubey, and replaced those memories and perceptions with the modified incubator Jyuubey.
However, this lone Puella Magi had a special power that corrupted the effects of the barrier and made it erase something different. This white-haired Puella Magi had a special condition known among other Puella Magi by the street name of "Brain Damage."
The Puella Magi launching a one-person assault on Asunaro City had a special kind of mind. Her mind was linked up and connected to a source where numerous beings would feed her information on her next move. These are entities that no being in her current universe, human, Puella Magi,incubator, nor concept, could fully fathom or grasp the idea of. However, as powerful as these beings are, they had only limited connection to white-haired attacker. There was a block in the system, something to prevent the massive overflow of information.
However, the Asunaro City barrier completely removed that floodgate. The entities now had completely control over the flow of information. With the system still in place, the girl originally came here for peacekeeping purposes and other heroic tasks. Once she entered Asunaro City, the block was removed. The mysterious beings assumed direct control of the hero of justice and had her carry out their plans instead.
Destroy Asunaro City and exterminate the Pleiades Saints.
One by one, the Pleiades Saints fell. One by one, each Puella Magi affiliated with that group was hunted down like animals. Bones were crushed. Bodies consumed and destroyed with magic. Soul Gems crushed beneath her heel or in the palm of her hand.
Black wings of grief flew into the air, blotting out the sun and covering her prey in the shadow of death. No member of the Pleiades Saints was safe from her, and her masters' all-seeing eyes.
The Puella Magi known as Sabrina has slaughtered all members of the Pleiades Saints, save for one.
Kazumi.
Sabrina did not need to find Kazumi, as Kazumi found her instead. The resulting duel between Sabrina and Kazumi was heavily swung in Sabrina's favor. Kazumi, a Puella Magi with great magical prowess in her own right, was not even a challenge for Sabrina, the Puella Magi that currently carried around her several hundred million marbles of grief around her. Kazumi was essentially fighting a Puella Magi that could form a massive wall of incredibly dense magic at any time possible.
Sabrina yelled, "I have a dream!"
Kazumi, puzzled at the white-haired girl's words, just asked, "What...?
Sabrina continued, slowly walking towards Kazumi, "That day every girl in this system will control their OWN destiny. A world of true hope, darn it!"
She pointed at the black hatted Puella Magi and set out a barrage of grief marbles at a high velocity. Kazumi was strictly on the defensive at that point. The amount of marbles being set at the girl was enough to completely block out the sun, leaving only tiny gaps of air for light to squeeze through.
She continued talking, explaining to her opponent her goals, "A world of peace, not war. Ruled by diplomacy, not slaughter."
Sabrina raised her warhammer and slung it over her shoulder, focusing on directing the grief marbles towards the dodging Kazumi. She said, "Where the magical girls make peace with each other and refuse to fight, not the other way around."
Kazumi was struck by a marble in the leg and sent crashing into the ground. Kazumi took cover behind a building that was torn down earlier from the barrage of grief.
Sabrina slowly walked towards the ruins Kazumi was hiding behind, increasing the kinetic energy of each marble as she closed the distance.
Sabrina kept talking to Kazumi, "Where power and justice are back where they belong: evenly divided among the people!"
Sabrina lifted her hammer and pointed it towards the collapsed building. The barrage of marbles stopped for a split second and all force was redirected towards the cover itself rather than the bit where Kazumi was hiding.
As Kazumi's cover was blown away, Sabrina yelled, "Where all magical girl is free to live --to act-- without fear of being killed!"
Kazumi took cover behind another building, but Sabrina sent that one crashing down with another barrage of precise hits on vital structural points.
Sabrina yelled, "Forget all these 'merciful' Soul Gem breakings and cryostasis podding."
Kazumi tried once more to take cover, but Sabrina knocked that one down even faster.
Sabrina kept yelling, "Forget all this 24/7 living in fear out of being hunted down by the Pleiades Saints for having some grief in their Soul Gem!"
Sabrina kept up the barrage, while taking a runners stance. Her wings of griefs stretched wide as she was about to charge at Kazumi. She kept going and said, "Forget 'rejection of the magical girl system.' Forget trying to reprogram incubators."
She dashed towards Kazumi, exceeding supersonic speeds, using her wings to fly slightly over the ground. While flying, Sabrina yelled, "Forget all of it!"
She pulled her warhammer back and sent it toward Kazumi's head. Luckily, Kazumi managed to dodge just in time so the hat was utterly obliterated, but not her head itself. Kazumi was still knocked down onto the floor from the intense wind pressure that Sabrina created. Sabrina tilted her body and repositioned herself for the chance of a second attack on the downed Kazumi. She used the spike and stuck it deeply into the ground next to Kazumi's neck, creating a tightly locked bar with Kazumi's neck between the hammer's handle and the hard ground.
Sabrina, lowering her voice, explained to the struggling Kazumi, "Asunaro City is diseased. Rotten to the core. There's no saving it as long as the Pleiades Saints are a thing -- we need to pull it out by the roots. Wipe the slate clean…"
She jammed her hand into the floating mass of grief marbles and pulled out a pitch black warhammer, created entire out of grief. Kazumi managed to pull the warhammer off of her neck and struggled to get up while Sabrina's back was turned
Sabrina yelled, as she turned around, "Burn it to the ground!"
The white-haired girl slammed the grief-made warhammer into Kazumi's back, sending her crumbling once more to the ground. Kazumi coughed for air, but Sabrina stomped her boot into Kazumi's back, preventing her from getting up.
Sabrina told Kazumi, And from the ashes a new Asunaro City will be born."
Sabrina raised her foot and stomped down on Kazumi's back again, yelling, "Evolved, but tamed!"
She leaned down, putting her weight on her foot and told her, "Magical girls will live together in harmony. The strong will not prey on the weak -- everyone living in coexistence. They'll make Asunaro City great again!"
Kazumi groaned out, "What are you talking about…?
Sabrina sighed and took her foot off Kazumi's back. She walked a few steps away and said, somewhat disappointed and annoyed, "You still don't get it. I'm using hunting the Pleiades Saints to bring peace… so I can end the Pleiades Saints hunting other magical girls."
Sabrina walked back up to Kazumi and grabbed her by the collar of her magical girl outfit. She brought Kazumi's face to to her own and told her simply, "In the new Asunaro City, magical girls won't be attacked and they won't waged war upon!"
She threw Kazumi back onto the ground and explained further, "Not out of anger. Not out of revenge! Not for what they're told is right by other power-hungry magical girls. Every magical girl will be free to live in harmony with other magical girls!"
Sabrina grabbed her warhammer off the ground and raised it to the sky with both hands and used her boot to expose Kazumi's Soul Gem. With one swing, she slammed the warhammer down and shattered the Soul Gem into thousands of broken shards.
She sighed and fell backwards. With a snap of her finger, she created a recliner chair with back, leg, and foot massage capabilities to catch her out of the spare hundreds of million grief marbles she still had. With another finger snap, she created her super fighting robot MECHA GUREN ZILLA LAGANN, with the reclining chair inside of the cockpit, to use to fly back home to Mitakihara Town. There were too many grief marbles leftover though, but there's nothing she could do at the moment about those . She would process them into much more efficient marbles later when she got back home.
Sabrina snapped her fingers for a third time and created a full symphonic orchestra out of some more grief for some music on the way back home. She activated MECHA GUREN ZILLA LAGANN's rocket thrusters and set the destination for Mitakihara Town.