Within a cave in the Forest of Menos.
"I'm sorry. I thought you wouldn't return to Hueco Mundo, so I hid Pikaro here."
Looking at the Pikaro running and playing all over the spacious cave, Tier said, "Pikaro's personality is no different from that of children. They even once opened a Garganta to the Soul Society just to play. Fortunately, they were discovered and stopped in time... But because of that, Aizen..."
Tier paused. Glancing at Iwao, who was surrounded by a group of Pikaro, she lowered her voice and said, "That lord believed he wasn't suited for the position of an Espada, so he eliminated him from the Espada and ordered him to guard outside Las Noches. He also ordered the Rúnūganga, which had no weakness apart from water, to imprison them in a sandstorm that raged year-round."
"As for why they're here, during an experiment on Zanpakuto, I accidentally released them. After that, they clung to me..."
At this point, Tier seemed to recall an unpleasant memory, and her expression became slightly troubled. "In the end, I couldn't shake them off, so I ran to the outer regions far from Las Noches. Then I came to this cave, which could conceal my presence, and used Second Resurrección. Only then did I subdue them."
"But... after that, they liked clinging to me even more. Since they also saw my Second Resurrección, I left them here and publicly claimed that I had killed Pikaro."
"That didn't arouse anyone's suspicions. Pikaro are rather special. Although each of them has an individual personality and thoughts, they share a single life."
"As long as one of them approaches death, the others will divide off a tiny amount of spiritual pressure."
"The way this spiritual pressure is transmitted is through a 'sound' inaudible to