Black Zetsu whispered inwardly. For the first time, his mind, as still as an ancient well for a thousand years, erupted into towering waves.
How was this possible?
In this era, aside from Uchiha Madara and Senju Hashirama, how could anyone else exist at this level?
And he was clearly protecting Nagato.
No, more precisely, he was "monitoring" Nagato.
Those Rinnegan were the most critical part of the Eye of the Moon Plan. They could never be allowed to slip out of his control!
Black Zetsu wanted to infiltrate, to draw closer, to beguile Nagato with the persuasive words he had honed over a thousand years.
But every attempt brought that cold "gaze" sweeping over him.
Like prey caught in the sights of its natural predator, his instincts warned him: one step closer, and he would die.
Not be killed.
Be "erased."
Vanish completely, in the very sense of his existence.
"...An unknown Kekkei Genkai clan?"
"Or... someone from beyond the moon?"
Thoughts raced through Black Zetsu's mind, but he could find no answer.
He could only lie low, huddled in the deepest darkness like a true shadow, and wait for an opportunity.
What he did not know was-
Atop the tower, on the observation platform.
Uchiha Ryūha stood in the rain with his eyes closed, yet a cold curve tugged at his lips.
The Hōgyoku Fragment slowly rotated in the depths of his soul, amplifying his reiatsu perception to an inconceivable degree.
Within several kilometers, the reiatsu of every living being, every fluctuation of chakra, and even... every trace of "malice" and "prying" was as clear to him as the lines on his palm.
That twisted, sinister aura of Black Zetsu's, steeped in a thousand years of obsession, stood out in his perception like a lighthouse in the night.