(Let's try to get top 20 fanfic rankings in honor of 100k words, so drop your stones and vote for Orihime!)
Bazz-B's hand lit up in flames and a solid flame blade two meters long formed from his four fingers. The flames generated from his body was as powerful as Yamamoto's Ryujin Jakka. In the original timeline, Bazz-B was able to use his flames to block Yamamoto's flames and leave his allies with only minor injuries. Oetsu threw the large tank on his back onto the ground and pulled out his sword, Sayafushi. Then he swung his sword at the large vat of jelly and destroyed it.
At his hip, Oetsu began to draw in the nearby spirit particles in rapid speed. They condensed and hardened after various energies mixed together with it. He was creating a sheath based on Orihime's memories and some physical theories from the human world. A large sheath appeared at his side which emitted so much static that it poured out of the opening and onto the ground. He grabbed the neck of the sheath and slid his sword in.
The static crawled up the blade and held it in place using electromagnetic force generated from spirit particles and Reiatsu grinding against each other. The sword was simultaneously being attracted and repulsed. The excess energy was infusing into the blade allow it to 'charge.' Bazz-B seemed to wait for him to prepare out of courtesy, but he was just bored of waiting and didn't want the fight to end early. Oetsu looked up after holding the blade into the sheath for a while and smirked.
"I would thank you for waiting, but I'm about to kill you so it won't be appropriate. This is my first time being able to sheath this sword so I got a bit carried away in my emotions. It'll end in a flash."
After he finished talking, there was literally a large flash of light which was as blinding as the sun. Bazz-B was momentarily stunned, but had good instincts. His flame sword came up on its own to block, but he didn't feel any resistance. After his vision adjusted again, he saw that Oetsu was facing away from him near the spot he was originally. The sword was sheathed but wasn't giving off as much power as before. As Bazz-B was about to speak, his arm falls off the joint at his shoulder.
"Ah, I missed. You've got some impressive reflexes. That attack was several times the speed of light. If I hadn't placed a barrier simultaneously the space in this area would have collapsed."
"Heh, your attack is strong but it takes a while to charge. I'll show you my true power! Vollstandig The Heat!"
A pair of blue wings and a Quincy cross appeared behind him. His flames ramped up and cauterized his wound. He pointed his finger and began to shoot several Burner Finger One's in rapid succession. However, Oetsu simply dodged them with minimal movements. Bazz-B then used Burner Finger Five and a vortex and flames shot out and surrounded him. Oetsu drew his blade and attacked with careful precision. The speed of his swing was enough to create a vacuum in space that caused the flames to change direction and implode.
The scene where Oetsu dies from a random shot through the heart appeared in his mind and he became angry at Bazz-B. Seeing one's own death from a different timeline wasn't easy to get over especially since Oetsu hid his dark and broody personality under his false exterior. Time slowed and his ego was stimulated by the power of hogyoku. Now that he got over his mental block and finally completed his greatest failure, Oetsu could sense Ichibe writing the true name for his sword. This was imperceivable for any other Soul Reaper, but he was the creator of Asauchi and Sayafushi.
"Wrong, you are no longer Sayafushi. Detonate, Hikari."
When Oetsu pulled out his sheathed blade and called its name, visually it did not change much. However, with a single swing, hundreds of miniature balls of light appeared in a line from his swing and created self-contained explosions. The light contained within the spheres burst out with as much force as a single full powered swing, multiplied by a hundred. Bazz-B released all of his flames at full strength in attempts to resist, but his body was torn apart like swiss cheese.
He laid on the ground bloodied and beaten. Oetsu walked over to him slowly and looked down at his eyes. They were filled with indignation and regret. Based on the original timeline, Bazz-B always wanted to defeat Yhwach. Oetsu began to slowly warp and change into Orihime, causing Bazz-B's eyes to go wide. When Amanozako appeared, she stabbed down into his heart. His body and blood were devoured and Orihime began to transform into him.
Bazz-B opened his eyes once more and his mind was flooded with more information than he could normally handle. However, the strength of his soul and body were enhanced by several folds. His memories aligned with the information from the original timeline which caused him to frown. Bazz-B's past was laid bare, and even the perspective of Jugram was shown which gave him a troubled expression. When he witnessed Yhwach's betrayal in the future, he became angry. His flames sparked and raged around him. The Quincy power was preserved. Rather, it was changed and became a new entity completely.
Bazz-B focused on the new blood flowing through him which gave his Heat an even more powerful kick to it. He was no longer restricted by the laws of three dimensions. His flames could penetrate directly inside someone and burn them from within without them even realizing. While he was engrossed in the potential in his body, no one noticed his previously severed arm melting into a blue light and disappearing. The bone turned to ash and then scattered in the wind.
Orihime released the transformation and returned to her normal form. She let out a huge sigh and laid on a patch of grass that wasn't destroyed. She stared up at the sky and slowly dozed off to sleep. It had been a rough few weeks focusing solely on her plan to defeat Yhwach. She was exhausted mentally and physically. When she woke up, she stood and walked over to the Gate of the World. This would lead her straight to the Quincy base in the shadow of the Soul Society.
The concept of where exactly their base was located always confused Orihime, but the inclusion of Bazz-B into the hive mind allowed her to come to an understanding. It was akin to a napkin folded over on itself. If one were to spill a drop onto this napkin, it would mark it all the way through. Then, if the same napkin was unfolded, it would have two identical drops separated by great distance. This was the basis to how the Quincy were able to create a world within the shadow of Soul Society. In theory, they existed in the same location simultaneously, but actually they were offset similarly to the principle of the napkin.
Orihime sat around relaxing and thinking about various things. Running into Bazz-B was a happy surprise. In fact, he was the most important Sternritter to acquire on this mission. With him, Yamamoto is no longer a threat. She will be able to run away at the very least. Additionally, he is the perfect candidate to rile up the other Sternritter. Many don't realize that Yhwach's ultimate plan is to turn them all into fuel for The Almighty. Only the top echelons are privy to this. Some are zealots and will accept it, others believe they will be spared.
With Bazz-B's memories, Orihime was even more confident to turn a few of the weaker Sternritter to her side. The goal of this mission was not to take out Yhwach, but to recruit as many Quincy as possible. They had a little under ten hours to regroup and plan an assault. Orihime's second target was naturally Jugram. Once she acquires the ability to give out her special Quincy bloodline, she can secure the new allies even if their powers get taken from them. She confirmed that even without Yhwach's powers, Bazz-B retained and even got an enhanced form of The Heat.
After gathering the Quincy and taking out Jugram, they would escape to Hueco Mundo. The perfect moment to strike was right when Jugram's power shifted back to Yhwach. The sun began approaching the horizon as Orihime transformed into Bazz-B and went toward the Gate of the World. His plan started when night fell. He knew Yhwach was arrogant and wouldn't bother to create a strange sleep pattern just to manage the power transfer efficiently.
As soon as the sun set, Bazz-B pressed the appropriate symbols and filled the gate with Reiatsu. The portal shimmered in a golden light and rippled. Bazz-B stepped forward slowly and the world around him changed rapidly. When his vision readjusted, he was standing in a grey-scale world that mimicked the Soul Society.