*
In other words, Oblivion Magia and this castle are not actually different dimensions, they have always taken place in the main universe. They are mere imitations, akin to how our genetic makeup allow us to awaken as magical girls and use our DNA as templates to regenerate our bodies, Oblivion Magia use our memories, lives, personalities and our interactions with the world to forge an imitation of the universe.
They are all conceptual magic, made to imitate another world down to the last details. Meaning that even creating an entire universe can be possible and cost effective. Even if they imitate the physical aspects of the true thing, they still continue to remain as conceptual constructs. Things rooted in reality exists and are stable, but concepts aren't that stable, their weakness are other concepts.
The castle material turns organic and rots, Hikari was assimilating with the entire dimension, it was a castle built by her ancestors so she might have a clear understanding of its foundations and exploit that. Kaede was the direct opposite, she didn't need any knowledge whatsoever. Her magic was the concept of movement and flow, the natural state of things and its alteration by her hands. With her magic, she could destroy all that is considered normal, bringing chaos and calamity.
The castle debris twists into a long rod before planting itself into Hikari's flesh, but at that point she was nothing but a giant lump of flash. She constantly expanded and contracted, convulsing disgustingly like a human being. It emitted immense warmth and raised the humidy as well as released an odor. But Kaede didn't need to stand there and simply accept an attack.
She proactively leaped with all her speed, causing reality to flow slower than herself as she passed the air, surpassing the speed of 'an instant' and she surpassed speed itself. Her rapier materialises in her palms with a familiar grip and an unfamiliar aura clad in pure white. The rapier exploded in a shower of white upon contact, dyeing the world in a storm of blinding light. Stopping the blade was a fleshy appendage that couldn't be called a hand.
Her ostentatious appearance seemed to have suggested that she had finished metamorphosising, she was more akin to a tree monster made of flesh than anything humanoid. It looked like fragments of armour and dense muscles had fused together to form a stick figure, but one thing was for sure. Her body had been made thinner to channel as much magical particles as physically possible. Each of her limbs were now 1 inch in width, her tead to her toes were also 1 inch in breadth each.
Her face was unrecognisable as she pushed Kaede down forcefully, her stick like limbs divided into hundreds of equal sized tentacle appendages that didn't look much different from before, pulling them back before punching with all of them at once. Kaede swung her leg, and with a powerful swing her leg sliced through a piece of Hikari's flesh like dried bark. Looking closely there was a tiny piece of aura coating her shoe.
Her pristinely shiny and pale leg didn't leave a single mirage as it moved as if it had always been there. It cut through the light made dimmer by Hikari blocking the light sources embedded in the walls. Her aura spread over her low white heel, causing it to glow with brilliance that could rival modern torches. The light cut through the darkness like a beacon, she looked to be glowing excessively, but an aura will always be an aura. In other words, she simply had that much magical particle waste being produced in her body.
Excess or used up magical particles end up as aura, leaking out of the magical girl like water from metabolical waste. Meanwhile, Hikari's amount of glowing aptly showed her drastically different approach to reaching godhood. Her spell brought organic matter beyond its natural limits, forging them together with magical particles to become semi spiritual. But Hikari achieved semi spirituality to perfection, meaning that while she was physically only half spiritual, she had gained the full capabilities of both spirits and corporeal beings.
Reaching full spirituality was not the only answer to reaching godhood, sometimes one simply had to grit their teeth and ram into their limits until the limits give up. Hikari showed that even mere mortals like her could reached the peak power through sheer will. While she might now be able to regenerate infinitely and deal devastating damage, it wouldn't be possible to completely get rid of bodily nerves.
Meaning that this abnormal state of being where she looks more like a stick insect than a Demon, she was presently feeling every ounce of pain that came concomitantly. Not only physical pain, but a psychological pain that was enough to mentally maim anyone was coursing through wildly around her body. But she had a strong enough will to ignore it completely. Her tendrils formed a drill shape which she threw from multiple directions, the number of her tendrils was innumerable and pointless to count.
Before the drills could reach Kaede's skin, they abruptly stopped spinning and even begun to rotate the other way round, the rotation reaches the base of her appendages and due to the perfect structure of her torso linking every muscle together for max efficiency, twisting a single muscle of hers twisted the entire limb off. A chunk of tendrils was ripped right off, then another, and another, and eventually all of them were gone.
She grew all of them back in an instant! She looked to be like a tentacle monster with the innumerable flesh appendages flying about at high speeds, switching up the tempo in an instant by adding some variety to her attacks. It was akin to watching an octopus monster learn how to fight. Most of the tentacles were used as a cover while some turned into drills discretely, awaiting the chance to strike.
But no matter how many appendages Hikari threw at her, Kaede could still observe them with her radar. This was a weak point of perfect organism further solidified by Kaede's observations, with infinite energy and mass, it was easy to pinpoint what Hikari was doing even without the use of her eyes. A simple generic radar technique could be used against Hikari if the individual trained it enough.
The appendages began to coil around her, ripping into pieces continuously while spurting a minute amount of blood that coated the castle floors. The drills were redirected into obliterating the other appendages, Hikari felt like she had no control over some of them despite them being part of her body. This was the next great weakness shared by Yiren, if not moreso for Hikari.
As far as 'perfect organism' magic goes, despite conferring infinite strength and endurance as a result of complete efficiency and magic conductivity, her muscles being intimately linked with the rest of her body was also a big curse. She had the perfect physique in terms of battle and dishing out damage but not receiving it. Well as far as 'damage' goes, her SS endurance still requires the annihilation of common sense and reality to overcome.
However once those are overcome... The intricacy of linking the whole body together causes it to result in her appendages to end up in a puzzle piece like state, where if an opponent like Kaede could use brute force to rip one piece out, the rest would come off like a deck of cards. But that has always been the case hasn't it? The moment somebody could overcome your defences, it should be common sense that they would deal considerable damage.
Perhaps it wasn't as big a deal as she and it in her mind. Hikari's mental strength was augmented by her SS will stat, so she might have some resistance to the mental dissonance and dislocation felt by her new body, though such a thing could never be verified. It was paradoxical for a person to have infinite mental strength as there was always a hard limit where one becomes impervious to all things emotional and mentally straining.
What's actually occurring in reality, was that the will stat's derived reinforced mental strength, is likely a percentage bonus sort of stat. It is the state of magic defence compounded with the strength of one's mental state, as those are intricately linked. Yet so, magical girls can still very easily break down. It wasn't as if they felt no emotions though some might. In the end, it is something mostly external. They can guard from mental attacks from other magical girls but not their own self willed emotions, their own worries are far more insidious and accumulates.
That is all to say, Kaede did not have the luxury to worry about others. Even with her new form, her survival persists due to her rather defensive stance on the present issue. The appendages began to layer themselves, forming rough devastating maces with a few layers of appendages which compounded their strength and durability. A straight throw was enough to sap the air of well... Air. The momentum and strength of her body crashed into the air, with not an instant that passed, the throne room had turned into a large vacuum chamber with low pressure.
But magical particles are not impacted by physical phenomena like that, their bodies drew in boundless magical particles from an infinite source and output it as aura. Aura at its base is an expression of magical waste, with infinite input, would there not be infinite waste? The pressure has not dropped one bit, the magical particles, specifically the suffocating auras are still there. If not for Kaede sending the incapacitated bodies out of the room, their auras would have killed even an A grade.
White and purplish black vie for supremacy in a chaotic equilibrium inside the room. There is no dynamic equilibrium, no clear distinction. Other than the excessively concentrated borders of aura around their skin, the aura all over the room splashes around like vicious and capricious magma.
Kaede summons her trusty rapier, but this time since energy was no longer a concern, it began to reflect all light instead of absorbing it to enhance itself. Her rapier released a brilliance rivalling the sun, a quartz white splendour rivalling the most reflective jewels. Purer than driven snow, Kaede finally releases a petty sneer. Finally grasping a chance at victory, she wanted to stay modest as an exemplar of her own character, but she couldn't hold it in.
With a single swing, even the indestructible castle walls split in half along with any appendages and thrones and Hikaris that stood in the way, leaving a gaping chasm. The appendages fell off her body but we're quickly merged with her body as if completely recycling it. Perhaps at this moment, Hikari was far closer to a giant amoeba. If she was as simple as such a unicellular organism, then it would explain the basis of a 'perfect organism'.
Was that what slimes were? Evolved bacteria through magical hypermutation? It's a single clue closer to victory, but also a distressing one. It meant that she had to eradicate every cell on her body to defeat her. It wasn't something her rapier which specialised in cutting and stabbing could manage. Regardless, she sliced through every appendage effortlessly, causing appendages to turn into stumps right after regeneration.
"... ~Pcefret eoitulovn~" (Hikari)
The appendages glowed with a dark purple light before its texture changed to a dark blue fleshy hue as the light subsided. Each individual appendage became harder to cut off as they began to take multiple hits to slice off. This had nothing to do with strength or endurance or quantitative stats for any matter. Kaede cut things up by imbuing the concept of 'move' or 'serrate' into her rapier with infinite magical particles. What Hikari had gained, was conceptual resistance to Kaede's rapier's concepts.
A % nullification of damage. If she swung wildly and repeatedly, the appendages still get punctured and eventually sliced off. But this was a stop gap, she had purposefully used less than her full power, she needed to adapt to her own newfound power, but that took time. Both were still improving in terms of combat in tandem. A rather troublesome tempo of battle that wouldn't allow one to rest for a single moment.
Keep improving, keep fighting. With every swing, a single white plane fills the room, as if building a new floor of pure white at the angle of slashing. Multiple floors of white form at once before she throws a final thrusting attack, unleashing a thin pencil sized beam of white light straight at Hikari's head. Hikari's body had been severed countlessly at once, with the final attack splitting her head open like a watermelon.
This time she learned her lesson. She prepared to send all of her energy into her rapier. Things would never end so easily. What's more she wasn't so conceited to be tricked the nth time. Her rapier started to glow with a wider reach and flicker rapidly. Just as she predicted, the cells that she couldn't eradicate regenerated instantaneously.
Between all the angles that she slashed as, what her attack did was seperation not destruction. She seperated her cells and then their components individually, but Hikari was like a slime. A single cell was enough to regenerate her entire body by pumping it with magic. Appendages flew at her from mid air, newly reformed in the vacuum of the throne.
"This brilliance will sever all, even the magic, your semi spiritual body." (Kaede)