Hueco Mundo, land of Hollows, land of Arrancars. A realm of truth, where only beasts could lay claim. No Shinigami or any other force could lay claim to the territory of the wicked spirits. Wicked to the usurpers, they were too busy quarreling with one another to really care too much about the goals and on goings of the other planes of existance, like the Soul Society. It was void, it was the darkness that only the strong could enter. An abomination in the plane of Hueco Mundo. Self-imprisoned. Ichimu was now free.