Kasek: The idea for this came when I read the spoilers for this week's One Piece. I didn't finish it on time, so apologies if there's already a fic on the site with this same plot. Enjoy! P.S. Spoilers for One Piece 598 and Bleach 421.
Disclaimer: I do not own either of the series used to create this story.
Aizen had lost all semblance of a cool demeanor. After being split in half by Ichigo's Mugetsu technique and being abandoned by the Hogyoku, Kisuke's seal was beginning to take hold. Why would he rather defeat me than let that thing be destroyed? "I despise you! Why does a man of your intellect sit idle? Why do you allow yourself to be controlled by that thing?"
Kisuke's expression dulled- he wasn't interested in having a conversation with the man who he had supposedly outsmarted. "That 'thing'? Do you mean the 'Spirit King'?" His expression changed slightly- the dullness became menacing. "Oh... so you saw it." This confirmed Aizen's suspicions- Kisuke had seen that thing. "Without the Soul King, Soul Society would split. The 'Spirit King', as we call him, is the 'lynchpin'. If the lynchpin is lost, then it will all easily crumble. That's the way... the world is."
Aizen could feel the last of his body being placed in the seal. "That's the logic of a loser! A winner must always think not of how the world is, but how it should be! I-!" The seal closed around his head, silencing him from the world. Ichigo had turned from the sight- it was pitiful.
Urahara walked towards Ichigo with a steadied step. "You've done well, Ichigo... if it weren't for you, my seal would never have activated. Well, considering how much damage you did, the seal might not have even been necessary... ah well. We'll be more prepared if there's a next time."
Ichigo looked back at the sealed Aizen- the seal took the form of three crosses made of light, intersecting through were Aizen used to be. "That Spirit King thing... what was he talking about?"
This earned a sigh from Kisuke's lips. "Well, I suppose it was foolish of me to think you weren't interested... This whole war was fought over the King's Key, after all. The Soul King- or, the Spirit King, as he is known to Soul Society these days- is... well, it's hard to explain with words. Words do not do the Soul King justice. I used to know a song that did, but it has been ages since I've heard it..."
He reached inside his coat and fumbled around, looking for something. "Well, with all that's happened, someone has to report to him. Might as well be us." He pulled out a key-shaped object from within his coat; Ichigo vaguely recognized it. "I-is that..."
Urahara nodded, affirming Ichigo's belief. "The King's Key... Yamamoto left it with me, surprisingly. I guess I was trustworthy after all!" He had at some point also taken out his fan and waved it in front of his face- the same annoying habit Ichigo still couldn't ignore. "Now, then... Shall we go, Ichigo?" He pressed the key into the air, and like the zanpakuto would do for doors to Soul Society, it seemed to fit into an invisible lock. The lock was suddenly quite visible, and a large, ornate gate soon followed. Oddly, it appeared that the gate was decorated with sheet music, only made of gems instead of ink.
Urahara seemed to read the music for a moment before smiling. "Oh, so that's how that song goes!" The gates slowly opened, and light could be seen pouring from the cracks... as well as sound. Lots and lots of sound. It sounded like there was a concert on the other side of the gate. Kisuke began walking through, and Ichigo hurried to follow.
On the other side of the gate... there really was a concert. Numerous beings all seemed to be attending the performance- Hollows, humans, Shinigami, Arrancar, even zanpakuto spirits and demons could be seen in the audience. On the stage was... a skeleton. Specifically, a very well-dressed skeleton, with a large golden crown on his head. He was singing and playing guitar, and to be honest, it wasn't bad, even if it wasn't to his tastes. Around the stage were shinigami captains, though they weren't people he recognized. They seemed to be guarding the stage from the audience, if the fact that they all had their swords released meant anything.
Urahara turned to Ichigo with a smile on his face. "That, Ichigo, is the Soul King, Brook. His music binds together all souls... there is no soul that doesn't like his music. The only person in the history of Soul Society who didn't like his music... was Aizen."
Ichigo felt the urge to kill, he really did. "This whole war was fought because Aizen didn't like that guy's music?"
Urahara tried to drag out his response. "Welllll, that's not exactly it, I mean, Aizen felt that he was a far superior being to the Soul King, so he set out on his own music career. It... didn't end well. From what I've heard, the final straw was when his own captain tossed out Aizen's music collection to make room for some of the Soul King's jazz pieces."
Ichigo began walking towards the door. "You people are insane. I'm out of here."
A random fan pulled on Ichigo's arm. "Aww, come on, hang around, he's going to sing his hit single, "Bone to be Wild" in a bit!"
Ichigo pulled his arm away. "No thanks! I have a life I need to get back to. This isn't even the kind of music I like, anyways."
Everyone around him paused, and stared. Ichigo was all of a sudden very uncomfortable. "...what?"
"BURN THE INFIDEL!" "HANG THE HEATHEN!" "CRUCIFY THE CRETIN!" "SHUN THE NONBELIEVER!"
Ichigo took that as his cue to run.