Chapter 1 - Unknown invaders
An overwelming force, like he could have never imagined before, startled even Kyoraku Shunsui, making him drop his cup of tea. His lieutenant barged into the room.
"Captain!"
"Yes I felt it too, we're going right now!"
As the top seaters of the eight division crossed the streets of seireitei they saw a lot of unconscious shinigami lying everywhere.
"It got the better of most of them.." Shunsui mentioned.
They ran onward, traveling to the west border of seireitei, the source of the burst of power. On the way they bumped into Mayuri and Nemu Kurotsuchi.
"Quite a heavy burst of power no?" Mayuri smiled, "it feels like a big part of soul society has just been destroyeeed."
"Your confirming just what I felt too Mayuri-san, now I can only hope that this time, your wrong." Shunsui answered.
The four of them were not the first to arrive, Captain Commander Yamamoto, captain soifon and captain komamura, all with their respective lieutenants had already arrived. The rest of gotei 13 arrived moments after, captain rose of the 3rd division coming in last. As the 26 strongest people of the gotei 13 stood before it the western gate opened. On the other side was... nothing. Literally nothing but sand was in sight anywhere behind the seireitei wall.
"Whaaat!?" The Captain Commander, obviously mad with anger rushed towards the deserted landscape, his hot reiatsu spreading out.
"Everybody, search the perimeter for the culprits!" As lieutenant Sasakiba finished his sentence the Captain Commander was already out of sight and everyone else started rushing in different directions as well. Except Captain Mayuri.
"I'll stay near the epicenter of the explosion for research, Nemu you stay as well."
"Captain are you sure this is the epicenter, how come seireitei didn't get hit by the explosion?"
"I'm not sure yet, Nemu, but it sure as hell wasn't a normal explosion. It's something the likes of the Gotei 13 has never seen before. It felt more like... an implosion."
A small silhouette came running from within seireitei, he carried something like a laptop and wasn't very quick with it.
"You... are right cap.. captain," Akon said catching his breath, "it resembles an implosion more then an explosion. Let me show you the charts"
Akon pressed a button on the laptop and it turned into a station with several screens and a lot more buttons.
"Hmm.. instead of an explosion, an outburst of reishi, it seems like all the reishi in the area was compressed into a small container and disappeared..." Mayuri mumbled.
"That's right captain, and for some reason Seireitei wasn't included in that compression," Akon answered, "but what about the unconscious people? Even I had a hard time staying conscious."
"Didn't you feel it Akon-san? Now I know for sure, it wasn't spiritual pressure like you'd think, it was the sudden change in Reishi that got to them. I'm almost inclined to say that some force absorbed rukongai.
By the time they came to this conclusion most captains had already returned.
"It's like this everywhere!" Captain Komamura said
"Just sand, where the hell did soul society go?" Captain Zaraki said.
Lastly, the Captain Commander had returned as well.
"You must have already realised as well, Captain Commander-sama, Rukongai wasn't destroyed, it seems it just disappeared into thin air." Mayuri said.
"Don't give me that crap you know it has to be somewhere!" The Captain Commander answered. "I can't explain this, but you are going to Mayuri-san. Search every realm, it has to be somewhere. Hueco mundo, earth, everywhere!"
"Akon-san...?" Mayuri inquired
"Such a huge amount of reishi we would have found in seconds, Rukongai wasn't transported to any know di..."
"Then find new dimensions!" Yamamoto ordered, "I'll be in my office I want a report within the hour."
All the captains and lieutenants returned to their respective headquartes, taking care of the unconscious Shinigami. Most of the Gotei 13 was still very confused. All they could really do was wait. As they were waiting the hour came to an end. The twelfth division still found nothing, but the captains still regrouped at Yamamoto's office.
"Good you are all together here, Captains!"
"What?!" Captain Commander Yamamoto raised out of his seat.
"Don't get so fired up Captain Commander, it doesn't suit you." A voice filled the room, not only that, it seemed to come from everywhere, even from outside the room. "Now I'm sure you want to know what happened with your lovely supply of souls. If you want to know you better settle down and let me talk."
...
"Here's the deal: Rukongai is safe and sound in a place where you will never find it. I am willing to give it back, but only if you are willing take part in a something I wanna set up."
"Don't be so vague, what do you want us to do? Who are you?" Captain Commander answered.
"I won't keep you waiting any longer. It's a tournament. Seven soldiers, my soldiers, want to challenge you for a great showdown. If you win, Rukongai will be returned unharmed. If the Gotei 13 loses it will also become part of our collection.
"Alright we'll do it, any more rules?"
"Just a few more but we will let you in on that tommorow. Meet me and my soldiers tommorow at this time, near the western gate..."
The voice disappeared.
"Any idea where the voice came from, Mayuri?"
"No Captain Commander, it seems to have sounded everywhere in Seireitei, but no apparant source."
"Soul society is at war! Get your whole division ready, the enemy is unknown yet. It seems like only eight persons, so they will have to be a very capable bunch to pull such a stunt! I expect you and all your seated officers at the western gate tommorow! At least now we have a goal, dismissed!"