Extracting Asura's Chakra had actually been a spur-of-the-moment decision by Soji.
If he had not found Asura's Chakra just now, he could only have extracted Naruto's instead.
As for the difference between Naruto's Chakra and Asura's Chakra?
There was one, in a sense.
Yet in another sense, there was none.
Though that sounded rather convoluted, it was the truth.
Put simply, Asura's Chakra was Naruto's Chakra, but Naruto's Chakra was not Asura's Chakra!
That was because Asura and Indra had continuously reincarnated throughout the Ninja World in the form of Chakra.
In this generation, they had happened to reincarnate into Naruto and Sasuke.
At first, since Asura's and Indra's Chakra had yet to awaken, Naruto's and Sasuke's Chakra could only come from their own training.
But once Asura's and Indra's Chakra began to awaken, although that portion of Chakra would also become Naruto's and Sasuke's—
—it still contained Asura's and Indra's wills.
Thus, influenced by those wills, the two would unconsciously become obsessed with one another.
After Soji extracted part of Asura's Chakra, Asura's influence over Naruto would be further diminished.
Furthermore, there was no question that Asura possessed powerful Yang Release Chakra.
Extracting Asura's Chakra directly was absolutely far better than extracting Naruto's.
And Soji did not want Naruto and Sasuke to be too deeply affected by Asura and Indra.
In Soji's eyes, Naruto was Naruto, Sasuke was Sasuke, and neither had anything whatsoever to do with Asura or Indra!
Naruto and Sasuke, as the people involved, likely felt the same way.
Otherwise, Naruto and Sasuke would not have reconciled in the end in the original story.
One had to know that the grudge between Asura and Indra, which had persisted for over a thousand years, would not normally be resolved so easily.
Only when Naruto's and Sasuke's wills