Somewhere in the Shinobi World.
Black Zetsu and Tobi stared at the tentacles before them.
Tentacles were surging from Uchiha Shisui's severed arm one after another.
The changes taking place in the severed arm.
Were something even Black Zetsu and Tobi White Zetsu had never expected.
Everything... was born from coincidence.
"It seems to be a new type of life-form..."
Black Zetsu murmured. He had lived for over a thousand years and accumulated a wealth of experience.
The implantation of Tobi White Zetsu's cells.
Had merely been one of Black Zetsu's fanciful ideas.
The product born by chance was the result of fate bringing things together.
Uchiha Shisui's cells... or more accurately, his Chakra.
Had combined with Tobi's cells.
And given birth to this strange creation.
"It contains incredible potential and Chakra..."
After observing it for a while, Black Zetsu made a decision.
"Tobi, try fusing with it."
"No problem~! Maybe I'll finally learn what poop feels like~!"
Tobi walked over while saying something strange and reached out his hand.
Very soon.
The tentacles born from the severed arm followed Tobi's fingers and surged into his body.
"Awooooo~~~!"
Tobi's body began to swell.
"I feel like my body is filled with power~!"
Splurt! Splurt!
Purple monsters surged from Tobi's body surface.
They snarled.
They looked far more ferocious than Mōryō's head.
"This is..."
Black Zetsu thought for a moment before finally understanding its essence.
"Tobi's cells... evolved?"
Konoha's Underground Base, Laboratory.
It had already been sealed off by Two and the others with the Four Violet Flames Formation.
Hyuga Sho stood inside the barrier, staring at Uchiha Shisui's corpse on the operating table.
Uchiha Saotome and his daughter... Uchiha Shisui's younger sister, Uchiha Kei, stood outside.
They watched from above, standing on the stairs leading down from the second