Disclaimer: Bleach is owned by Tite Kubo. Naruto is owned by Masashi Kishimoto. Any ideas not recognized in the Bleach and Naruto timeline are my own.
Hope you enjoy! Thank you for reading :D
In Soul Society, an orange-haired ryoka Kurosaki Ichigo is on a mission to save his important friend, Kuchiki Rukia, at the execution stands. There, he fought and defeated the 6th division captain Kuchiki Byakuya. And now, he rests thinking that everything was over, but who said everything was over?
In a forest, the 2nd division captain Soifon was crying in defeat. Standing across from her, Shihouin Yoruichi was covered with butterfly tattoos on her arm and face and on her black clothes. And now, both were looking up in disbelief. It looks like new problems have arrived.
In fact, most people in the vicinity were "looking up" in disbelief, except for 12th division captain Kurotsuchi Mayuri, who took no interest in it.
Back at the execution stands, 6th division lieutenant Abarai Renji, Rukia, and Ichigo are fighting against 9th division captain Kaname Tosen, 5th division captain Sosuke Aizen, and 3rd division captain Ichimaru Gin. Aizen had been researching about the process of transforming Shinigami into Hollow and vice versa, creating an incomplete Hogyoku. Similarly, former 13th division captain Kisuke Urahara had also created an incomplete Hogyoku. But, Urahara later saw this as dangerous, so he wanted to destroy it, only to no avail. Out of desperation, he turned to sealing it in an unsuspecting soul - Kuchiki Rukia. Consequently, Aizen targeted Rukia and successfully extracted the Hogyoku without harming the container herself.
After extracting it, Aizen was surrounded by Yoruichi and Soifon; Gin and Tosen by 10th division lieutenant Matsumoto Rangiku and 9th division lieutenant Hisagi Shuhei respectively. All of a sudden, three giant pillars of light came down from the sky full of Menos and illuminated Aizen, Gin, and Tōsen. 7th division lieutenant Iba Tetsuzaemon yelled at them, "Trying to run?!" and was about to start charging at the three, only to be stopped by the 1st division and oldest captain Yamamoto Genryusai Shigekuni. "That beam of light is called 'Negacion.' The Menos use it to rescue their comrades. Once that light is cast, it is impenetrable from the outside. Aizen has gone out of our reach."
Out of nowhere, a voice sounded, "That is not true." A spiky blond-haired man appeared, draped in black Shinigami clothes and a white captain cloak with the number "14." His red-embroidered katana's sheath and hilt were tied at his waist, next to his left arm.
Ichigo turned to the direction of the voice. That's not possible. I thought there were only 13 divisions in Soul Society? thought Ichigo.
Sensei, what is he doing here? He isn't supposed to be back until a month later because of his mission. How is he back so soon? thought Aizen.
Naruto shunpoed to the light barrier that enveloped Aizen. He kneeled and touched the ground. Naruto recited, "Fall upon the earth. Ye thy Lord. Scratch the sky and break it open. Bakuhado #75 Kurakku."
Just as the barrier vertically cracked open, a new barrier was in place. Naruto was about to cast the incantation again, only to be intercepted by several red high-density energy beams. "Cero…," Naruto whispered, "How annoying."
As Aizen ascended to the sky, 13th division captain Ukitake Jushiro questioned Aizen, "What are you trying to do?"
"To go higher."
"Have you fallen in the process, Aizen?!"
"You are too arrogant, Ukitake. No one starts on top of the world. Not you. Not me. Not even the gods." As Aizen slicks his hair backwards, he confidently proclaims, "But the unbearable vacancy of the throne in the sky is over. From now on, I will be sitting on it."
"Goodbye, Shinigami. Goodbye, sensei. Goodbye, ryoka boy. For a human, you are really interesting." Aizen smirks and with Gin and Tosen, disappears into the darkness with the Menos.