Generally speaking, Black Zetsu could not be killed. Even if he was killed, he could revive as long as Kaguya Ōtsutsuki remained alive.
But Uchiha Shunichi had not chosen to kill Black Zetsu. Instead, he had broken him down and absorbed him, turning him into something resembling the Ōtsutsuki Clan's "pills."
The thing looked utterly disgusting. In reality, though, it already qualified as an inferior Chakra Fruit!
A thousand years ago, Kaguya had hunted down powerful monsters everywhere precisely to refine them into "pills" and increase her own chakra.
Through that process, the powerful monsters of this world had gradually died out. By now, those creatures had either become summoning beasts, been sealed away, or vanished altogether...
Holding the "pill" refined from Black Zetsu and half of Kaguya's arm, Uchiha Shunichi did not eat it. Instead, he took out a scroll and sealed it away.
He was not like those members of the Ōtsutsuki Clan who would eat anything. Chakra of such low quality held no interest for him.
Kaguya hovered in the air, staring expressionlessly at Uchiha Shunichi. She was now furious beyond measure, but wisely chose not to keep attacking.
The flesh on her body writhed, and soon her severed arm had regenerated. Although Black Zetsu could never return, ordinary injuries meant nothing to Kaguya.
"Kaguya, after all this, do you still think you have a chance of winning? If you're willing to surrender, I could let you live a peaceful life," Uchiha Shunichi said to Kaguya in the sky after finishing everything.
He genuinely meant well. After all, if Kaguya only wanted a quiet, peaceful life, that would actually be easy to arrange.
Unfortunately, Kaguya ignored his words entirely. Contempt for these ants showed in her eyes, and her body suddenly began swelling at tremendous speed...
"Careful!