Formidable?

"Captain Orihime Inoue requesting space to be frozen within 5 kilometers of my location. Please have a Gentei Kaijo pending, opponent potentially has captain-level strength."

"Confirmed, locking space in a minute, please standby."

Orihime put away the Denreishinki, a cellphone useful for communication with Soul Society. BG8 didn't seem to react to her talking with Soul Society and let her sort it out. She was still shimmering in Reiatsu from her abilities. She looked over at the strange Sternritter. The chain gun that he attacked her with was hidden beneath his overcoat. Orihime got into a low stance and exhaled slowly.

Her Reiatsu kept climbing as two vortices formed which circled from her arms to her back infinitely. This was Soi Fon's technique that the two of them developed while training. Once activated, it could be kept indefinitely since the Reiatsu is contained within the vortex on either side. This version of Shunko, named Mukyu Shunko, was extremely compatible with Reikoromo. Both techniques could remain active indefinitely, and even exponentially increase the longer the fight went on due to the adsorption of spirit particles.

Once the minute went by and space was locked in the area, preventing any permanent destruction, she launched herself at BG8. Her Shunpo under these two effects was one of the fastest speeds in Soul Society, only losing out to Yoruichi and Soi Fon, since they were built for speed. Orihime favored burst damage more.

When she collided with BG8, it seemed that he did not react, however, beneath his cloak, several compartments opened and missiles shot out toward the oncoming Orihime. The cloak flew backward and twelve missiles landed on Orihime. However, due to the pressure and speed, most of the missiles didn't even touch her. The ones that did were shrugged off by her Reiatsu reinforcement.

BG8 jumped backward in attempts to avoid her strike, but she still managed to clip his abdomen. A thin beam of golden light the same width of her fist shot out for several kilometers, causing mass destruction. Orihime only managed to leave a small wound on his side which caused her to click her tongue. The spiritual Limiter was really frustrating.

"Your data has changed slightly. No matter, the more Knowledge I gain from you, the more His Majesty will develop His army!"

"You're really annoying. Aren't you afraid of revealing yourself too early?"

"Hmph! How dare you question His methods?"

His arm opened up and the large chain gun appeared. He began to fire it off at Orihime, but she was able to easily dodge every hit. Her instinct told her that these bullets could penetrate her Reiatsu cloak. This was frustrating, she had to resort to bankai to break through his defenses and take him out in one go. Her hair began to turn black and the orange Reiatsu creating a vortex around her changed to purple.

"Bankai, Hanayo no hime. I'll end this quickly, try not to blink."

Although she wasn't the fastest in her released form, due to the unique properties of her bankai, she could move along a fourth axis. This not only hid her movement completely from three dimensional beings, it also ignored typical conventions for distance. She arrived next to BG8, and struck out with the side of her hand.

BG8 did not have any Knowledge of the fourth dimension and was completely caught off guard. His torso was bisected as easily as cutting tofu. His adjustment to her normal Reiatsu was useless against her when she transformed. The nature of her Reiatsu in her partially transformed bankai was completely different from her normal form. However, she didn't expect the upper half of his body to sprout tendrils and reattach itself.

Simultaneously while reattaching himself, he attempted to pierce Orihime with his tendrils to gather more data from her. However, she stepped backward into the fourth axis, causing him to lose track of her. Upset at this development, she pushed her transformation to the next stage. Her sclera turned pitch black and her iris disappeared. Her eyes became completely black, but she gained the ability to see in the fourth dimension.

What this meant was that she could now see through and inside all objects. The internal structure of BG8 confirmed her suspicion. He was completely inanimate. However, there was a core made out of blood which seemed to be the source of his power. It was situated in his head. BG8 saw the change and released all of his tendrils.

Orihime moved around in the fourth axis and appeared in front of him. All of his tendrils shot out behind him, having misread her movements. She slammed her fist into his helmet, destroying his head completely. However, at the last moment she saw the core move into his chest cavity. She attempted to follow up with a second attack, but BG8 broke off into five pieces and then reformed out of her range.

She attempted another sneak attack, however, his tendrils wrapped around her arm accurately. She had moved along the fourth axis again, but it seemed that his Knowledge collecting capability was far superior to what she had assumed. In the original timeline, BG9 was defeated by a full powered bankai from Soi Fon. Even then, he did not die. BG9 was taken back to Yhwach where he was executed and converted back into Yhwach's power.

Orihime did not want to admit defeat and delayed requesting for the limiter to be released. She shifted the equal flow of Reiatsu from Shunko to the arm that was trapped, causing the tendrils to get ripped apart from the force. She then shifted the force to her other arm and struck out again, destroying a part of his torso. Black blood had been pouring out of the wounds she gave him, which caused him to retreat and stagger.

The ground shook and BG8's Reiatsu spiked. A Quincy cross appeared behind his head and a pillar of blue light shot into the sky with BG8 in the center. After it cleared, what remained was a fully healed BG8 with several tendrils that now had various knives and instruments. Additionally, there was a pair of miniguns at his hip and a rocket launching device peeking over his back. He seemed to be fully kitted out now. Orihime thought this was likely his Vollstandig, and his words confirmed it.

"I am BG8, and my designation 'K' stands for Knowledge. My Vollstandig is able to calculate a thousand times faster than in my normal form and gather data from much larger distance. No matter what you try against me, I will quickly calculate and counter it."

"Is the Gentei Kaijo ready?"

"Affirmative, sending it now."

A lily of the valley appeared on her cheek and she spoke the release words. Her spiritual power multiplied by five nearly causing BG8 to drop to the ground. She sighed and slowly walked forward toward the Sternritter. With her full strength released, her mind cleared. The difference in power was too great for him to deal with.

Orihime's lips and fingernails turned black. A silver mask began to materialize over her face and long silk gloves over her hands. The visual effects of Shunko were no longer visible due to melding with the fourth dimension and Orihime's body began to be partially transparent. However, unknown to either of them, BG8's Vollstandig form allowed him to collect data from the fourth dimension.

BG8 never had to do such a thing, therefore was never aware of it. However, now that he was facing someone like this, he could clearly see the horrifying scene in front of him. Orihime walked slowly as she entered into the complete transformation. That alone wasn't very impactful. However, behind her a behemoth like creature was forming.

The creature seemed to ignore space and occupied an area beyond the means of measurement. Its body was completely black and smokey. The source of this smoke was from Orihime's back. It continued to pour out from her forming a larger and larger monster. Eventually two white slits appeared that opened. What BG8 saw were two completely white eyes with his life reflected on them. He could witness his first memories as BG1 and the cumulative knowledge he gained for His Majesty.

Its eyes flickered like a movie projector as his whole life was shown to him. After the 'movie' ended, another slit appeared below it that went from one end of the creature to the other. It opened up and revealed a maw filled with rows and rows of teeth. Each tooth was pristine white. The creature seemed to be smiling!

"Don't worry, it'll be an agonizing death."

"Get… get that thing away from me!"

BG8 felt fear for the first time since facing an angry Yhwach. Orihime waved her hand down and an invisible force assaulted him. However, he could clearly see that this was no invisible force, it was in fact the smokey visage of the giant behemoth behind her. Its maw surrounded him in all directions and he fervently tried to calculate and defeat this creature with Knowledge, but he did not even understand its origin.

His soul began to break down into several small pieces as he was shredded by those teeth. Since he was an artificial soul created by Yhwach, he was especially weak to attacks that destroyed the soul. All he remembered was excruciating pain from getting his soul ripped apart. BG8 slowly drifted off into eternal slumber, his cold husk fell limp onto the ground.