Isshiki sensed danger.
That power belonged neither to the Ōtsutsuki nor to any known system in this world.
It was something entirely new, unknown, and fraught with menace.
What unsettled him even more was the jumbled fragment of information Shiro had sent back before she was destroyed. One name appeared repeatedly within it:
"Uchiha Ryūha."
Isshiki searched his memories for that name but found nothing. A thousand years ago, he had never heard of this person.
What had happened to this world over the millennium he had spent asleep?
He tried to connect to his other "vessels," but most were dormant or blocked by some kind of power.
Only a handful remained accessible, but the information they sent back was fragmented, making it difficult to piece together a complete picture.
An unforeseen variable had emerged in this world.
Isshiki realized he had to accelerate his revival.
His original plan had been to awaken fully in three years, once the advance force arrived. Now, however, he could no longer wait.
He needed a new "vessel," one powerful and pure enough to bear most of his consciousness.
Deep within the ley lines, he spread his senses outward, searching the entire planet. Countless living minds flashed through his awareness, but most were too weak to merit his attention.
The few powerful ones each had their own flaws or were protected by some kind of power.
Then he sensed "that being."
It was a twisted, dark consciousness filled with hatred. He had no physical form, only pure will, an obsession that had endured for a thousand years.
He was weak, but unique-born from the power of the Ōtsutsuki, yet independent of them.
He was a product of Kaguya's will, yet had betrayed her.
Most importantly, his knowledge of this world far surpassed Isshiki's own.