Hueco Mundo, Las Noches.
This was the place with the highest Reishi density among the Three Realms, far exceeding even the Soul Society, which was entirely constructed from Reishi.
Ever since Barragan Luisenbarn had been effortlessly defeated by Kyoka Suigetsu, Hueco Mundo had taken on Aizen's shape.
Moreover, as the number of Arrancar continued to increase, the once chaotic Hueco Mundo, governed by the law of the jungle where the strong devoured the weak, gained order for the first time.
Although that order was founded on tyranny and dictatorship, having order was always far better than having none.
Most importantly, Hueco Mundo had gained the power to confront the Soul Reapers of the Soul Society head-on for the first time.
Quite a few who had once been hunted by Soul Reapers and hated them to the bone were sharpening their blades, preparing for a grand battle.
While these new ideas occupied the minds of the simple Hollows, Aizen's attention was entirely focused on merging the two Hogyoku into one.
Clearly, accomplishing that would not be easy.
The Hogyoku was originally a crystalline body formed by compressing countless souls. Both its internal and external structures were remarkably stable.
And stability meant that for either one to "devour" the other would be exceedingly difficult.
It was not as though there was no way at all, but every currently known option was unbearably slow.
At that thought, Aizen suddenly looked up and asked, "Has there still been no news of Allen since he vanished in Karakura Town?"
"No. As far as I know, he had a minor conflict with Kisuke Urahara, the Visoreds, and Toshiro, captain of the 10th Division, before disappearing without explanation." Gin Ichimaru quickly provided the intelligence he had gathered.
To be honest, he simply could not understand why Aizen,