Only after a long while did Shimura Danzō recover his senses. Remembering the moment of his death, he roared at Yechen.
"It was you! You evil Uchiha brat! You actually dared to kill me! Is the Uchiha Clan planning to betray the village?"
Yechen had originally wanted to say something, but the sight of him like this drained his interest. He simply watched him put on his performance.
At the same time, he released his spiritual power to sense the changes Impure World Reincarnation had brought to Danzo.
At first, he had been surprised that Orochimaru's first reanimated subject was Danzo.
After all, he had killed Danzo himself, and even dragged his corpse deep underground. His body had probably long since been reduced to bones.
To perform Impure World Reincarnation and pull someone's soul back from the Soul Realm, the caster needed at least a strand of hair or a genetic sample as a medium.
And that requirement only applied after Orochimaru and Kabuto Yakushi had improved the technique in succession.
Right now, Orochimaru had only a preliminary grasp of Impure World Reincarnation, so its requirements should have been stricter.
A piece of flesh, for example, or a body part.
Clearly, Danzo, who had been dragged deep underground to nourish the earth, could no longer provide anything like that.
Yet Orochimaru had managed it.
That left only one possibility: Orochimaru already had a tissue sample from Danzo's body.
Thinking of Yamato's creation through the integration of hashirama cells, and Danzo's later transplantation of an arm bearing Sharingan, Yechen felt this was entirely possible.
An ambitious man like Shimura Danzō might have asked Orochimaru to research ways to combine hashirama cells and the Sharingan long ago.
In that case, obtaining tissue samples from Danzo for experiments would have been perfectly normal.