"Finally, we're back!"
After settling matters in the Shinobi World, he left the Five Kage and the ninjas he had contracted as Servants temporarily in charge of Chaldea's operations, though there was hardly anything to operate in the first place.
After all, this Chaldea was not the original Chaldea. It had neither high-tech magecraft facilities nor a Spiritron calculation device capable of sending human Masters into lostbelts. With only Semiramis's Hanging Gardens of Babylon serving as its main base, it seemed rather bare and shabby.
Then Ye Uchiha selected the world-travel function and returned to the Shield Hero World.
The Mangekyō in his eyes spun, then rippled as they transformed into purple Rinnegan bearing six concentric rings. Some invisible, immense force seemed to tear the void open, revealing a chaotic darkness within, and a group of figures stepped out.
His dark brown eyes flickered faintly as Aizen surveyed his surroundings with curiosity and murmured, "So this is another world?"
Beside him stood six Heroic Spirit Servants, including Emiya, Scáthach, and Enkidu, as well as four of the Shinobi World's greatest fighters: Hashirama Senju, Madara Uchiha, Sasuke Uchiha, and Naruto Uzumaki.
Amenominaka could instantly transport its user and anyone nearby into another dimension. Its accessible dimensions included lava, ice, supergravity, sand, and acid, and all five connected directly to the core dimension.
This had originally been Princess Kaguya's exclusive dōjutsu, but for some reason, the ability Ye Uchiha's Rinnegan had awakened also allowed him to control Amenominaka Space. Perhaps his Servant contract with Princess Kaguya allowed her Amenominaka Space to be shared with him.
That was Ye Uchiha's guess.
Activating Amenominaka required enormous amounts of chakra and ocular power. Had Ye Uchiha not awakened a Wood Release sage body, the Eternal Mangekyō, and the Rinnegan, along with having Kenos's cloned Nine-Tails