*
"I've caught up. Regardless of your will, your [Disaster] has been broken through and your regeneration overwhelmed.
You've lost." (Hikari alternative)
"... Did you think because I was a fake, that I would be more killable than you? " (Hikari)
Speaking strictly, she was not the fake. In her own rightful world, she was the one and only Demon King, biological perfection and weapon of mass anti human destruction. There was no other like her. Everytime she was referred to as a fake, Alter was explicitly referring to [Disaster]. While there is no definite relation of time between worlds, making distinguishing who achieved [Disaster] earlier an impossible task, it was firmly believed that Alter's [Disaster] was the original that lead to the Hikari's of other worlds awakening their own [Disaster] like a chain reaction.
What caused the apocalypse and ended the contemporary age of human civilisation and technology was a subconscious awakening of Hikari's [Disaster]. It was no one other than the Hikari of Kaori's world, even if the awakening was a result of Alter's [Disaster] spreading death and despair to other worlds, the destruction and magic was directly caused by Hikari.
"All this while, I've been thinking. What makes you the original? Because your [Disaster] awakened first and caused the other [Disasters] to be awake in a chain reaction? Or was it the fake that their skill names contained the word 'imitation'?
I've realised I've been worrying over losing so much that it's all I can think of. If I come out winning, yet I can only think about how not to be defeated... For the rest of my life... Then did I really win?
If I keep obsessing over my own demise, am I really living what I set out to do? Anyway, crossing this barrier in my thoughts is only the first step. " (Hikari)
She wasn't dying, she wasn't being corroded by Alter's [Disaster]. Rather, she was already corroded. Her physical body no longer existed, she no longer existed in the world. She doesn't exist, thus she cannot be killed. She had become 'used to death' and being in a state of nonexistence, that she could persist in such an impossible manner. After losing once to Kaori, this was the result. Existing in a state of nonexistence, a contradictory being that can never be resolved. In all meanings, reality has malfunctioned and allowed her to persist after dying, in other words the concept of death no longer affects or relates to her.
"... Transcend your own truth, a shattered but glamorous heart, [The Great Disaster(resolved)]." (Hikari)
Her body glowed brilliantly, blindingly, as if changing the world into a beautiful heaven, a picture of paradise with unlimited hopes and dreams. Ironic coming from a Demon King, in this state she naturally had infinite stats. Rather than using [Disaster] to raise her base stats to infinite, now her base stats are infinite. Her natural state in other words, has grown in comparably stronger. It was odd for sure, it was the acceptance of her situation rather than her resistance that brought her this far.
However acceptance did not mean passivity. She could accept the situation and still wish to change it, in this case the main component is acknowledgement of her weakness. That her 'perfect biology' is much less than 'perfection'. Rather than be the fake that is as powerful as the real deal... She has resolved to surpass the original with all her might.
She walked towards Alter, raising her fist, she casually swings it down. It phases through Alter's chest. Nothing happens for a bit... Then blood explodes out of Alter's chest.
"...?! My fate... My existential tie to divine retribution and punishment is gone..." (Hikari alternative)
The light on Hikari's body fades, revealed under is a wedding gown. She wore sleeveless gloves that stretch to the middle of her back arm, under a band of white it became transparent grey all the way to the wrist before turning back into a smooth and soft white like whipped cream. From her neck, a small white rose connects to a black collar that stretches over her chest and under armpits in transparent grey, before ending in a white on piece dress. Between the one piece and the collar was a transparent grey film with beautiful black embroidery.
A large black rose decorates the side of her dress by sitting on her hip, it had black veins that spread into every direction, tying around her waist and left leg before they ended. Hikari faces Alter once more, Alter takes a step back in weariness and a tinge of fear. What should she do now? What could she do against someone that could not 'die'? Coating her body in [Disaster], she awakens... She would never let the battle be one sided, she would awaken as many times as there are universes if it allowed her to win.
Despite both sides boasting 'perfect biology', there was no such thing as 'perfection'. It would be too abstract and conceptual to create, in the first place what did 'perfection' mean? Of course, the only definition that mattered is the one that Hikari used. In other words, their biology was only perfect in design towards the intended use they had in mind, it didn't mean that they were unbeatable...
In the end, they both accepted their weaknesses and evolved on the spot to compete with the other. Hikari and Alter were both individuals who were willing to accept their own faults, showcasing brilliant humility and will to improve. Alter began to glow a dark black light, covering the world in streaks of black that spread beyond the foreseeable range. When the strips of black light covering her body popped open and vanished, an elegant black dress was revealed underneath. Its design was much similar to Hikari's wedding dress and had a complex design that anyone would boast of.
"A destined weakness paradoxically carved by the past rather than the future, assimilating it I gain a new possibility.
Only with the irrationality of magic which acts on 'rules' rather than calculations can such an absurdity come into fruition. My thoughts harbour an endlessly struggling wit, so what if I lose my superiority as the 'original'?
I will not let you win. Beyond my all, I will put that much into defeating you! " (Hikari alternative)
" That's been the plan from the start. Glad you caught up. " (Hikari)
Spitting back venom, Hikari leapt. In one step she arrived right in front of Alter and slammed her fist forward. Alter caught it with her palm and sent her own fist. Drills of [Disaster] conjured from thin air and slammed into Alter's fist before dissipating into nothing. Alter's attack destroyed Hikari's [Disaster] through sheer force. However, even without that, both of their [Disaster]s have gained new traits after the evolution.
"[Disaster - annhiliation]. " (Hikari Alternative)
"[Disaster - wander]." (Hikari)
A black wave of magic shot out of Alter's arm towards Hikari, before an additional black wave conjured in front of Hikari and deflected Alter's wave. Both of their magics have evolved on the spot and extended past their initial function, branching off into endless possibilities. Their new abilities were quite self explanatory, Alter's new [Disaster] emulates Arasovi's [Destruction] with 'annhiliation', Hikari's emulates Kaori's [Calamity] with 'wander'.
In one step, Hikari's left leg lands next to Alter's, she swings her right hand coated in [Disaster - wander]. It lands right on Alter's knuckles, their punches collide violently against he backdrop of the universe, tearing physical laws apart and churning them into fodder. Cracks in space time spread like a network of spider webs, reaching ever further into the endless expanse of existence. The cracks grow larger and wider, swallowing universes whole an drowning them in [Disaster]. As they fought, the number of alternate world's affected by [Disaster] only increase.
It wasn't as if Hikari's mission was to stop [Disaster] from spreading further, so such a consequence was less than trivial to her. Hikari swings her right hand to the left, her palm spreads and her fingers clump together to form a hand blade. Her wrist flicks with aggressive force that pushes back Alter's fist and breaks off the stalemate. Hikari brings the same wrist up and to the right, coating it deeply to deflect any magic aimed at her.
Surpassing Hikari's speed, Alter throws a fist towards her, but it slips past her neck and flies behind Hikari. The resulting shockwave alone was enough to cleave her neck in two, sufficient to kill any low grade magical girl. Without worth mentioning, Hikari survived effortlessly as her neck recovered at a speed that would make others doubt their eyes. Though at this stage, any bystander would have trouble observing the attack in the first place before they try to see any wounds.
Exploiting this chance, Hikari spins her entire body into throwing a high kick that slams into Alter's face. Alter's body was thrown far off into the distance, to which Hikari catches up to spin out a side kick. Her heels lands on Alter's waist, crushing into her ribs and ejecting blood out of her lungs and throat. Dark crimson fluid flies out of her nose and mouth as her body vanishes. Alter reappears behind Hikari, the blood gone from her face and her wounds were completely gone.
She throws an under arm punch and impales Hikari while injecting [Disaster - annhiliation] into her body. In exchange, Hikari lops off her head by spinning her entire body around the impalement site and thrusting her leg to the side, taking Alter's head with her heel. Hikari spits out a black fluid, [Disaster - annhiliation] was counteracting against her regeneration and melting her organs into mush. She couldn't recover with the magic running rampant inside her body. But there was no need to.
This will be her chance, this will end the fight. [Disaster - wander], at first glance it was an emulation of [Calamity], but... Why should she satisfy herself with a mere copy of Kaori's final skill? Obviously... She would try to surpass Kaori at all cost. Even abandoning her own personality and mission, she would force herself to reborn into a new entity if it granted her the strength that she needed. Kaori herself is technically no longer around, the present Kaori is an amalgamation of Kaede, Kaori and Himei.
Essentially, every person is but a chaotic mess of experiences and feelings compiled into one decision making ego. The same goes for Kaori, even if she was physically fused with the other personalities. There was no leading personality, everyone that had been in Kaori's body were equally assimilated into a new being. If her parents were to ask if she was really their son, she wouldn't be able to answer confidently. But that was simply how life went. Hikari must assimilate all demons in existence, all living beings. She would achieve godhood in a certain sense a second time, attaining omniscience through absorbing the fate of every living being...
Her original personality would amount to nothing, lesser than a drop of water in the ocean. Using [Disaster - wander] she redirects the memories of every living thing in existence towards her, then consumes them with [Demon King constitution] which changes her own body composition with magic. Akin to gaining the abilities of every demon in her kingdom, this time it was every living being... That was the only way she could surpass her self. Even Alter's memories have become a tiny byte in the library of her mind.
Ascending one last time, there was now simply too much for [Disaster - annhiliation] to destroy. Unless...
"[Disaster - annhiliation], in other words, the complete elimination of a target from existence. Surpassing [Destruction], it deals a strict damage that matches 100% of a person's existence. Nothing will be left." (Hikari alternative)
"Any new mass I gain will be accounted for in that 100%... 100% of my existence will be destroyed by an unprecedented disaster.
However, I could still surpass 100%. If the extra mass I gain is accounted for, then I can't surpass 100% by increasing mass or matter in my body. I have to take it from somewhere else, and control it without fusing it to my body. " (Hikari)
"... Huh? " (Hikari alternative)
What better target for this move she was about to pull... Than the individual right in front of her? Instead of taking memories and assimilating like Kaori... She will lose her own existence another way. She was going to die no matter what, she has to resign herself to that fate. The Hikari here and now will not see another second more. Then, she has to preserve her existence some other way. Throughout history, humans have tried to leave signs of their existence behind through artifacts, literacy and culture.
But what if there was another option? Rather than absorbing and fusing multiple existences together, she will split. Hikari will give her memories instead of taking them, sending them to Hikari Alternative, she drowns out Alter's personality with her own and takes over her body and destiny. Alter was still around, now part of Hikari's being. But the main personality in charge now was Hikari.