-Shikigami: Causal Severance!
A white streak flashed past, and the shadow of a Shikigami appeared behind Gandharva. Unlike the mere "outline" Ikaruga had seen when he destroyed the Amachi Karumi Shikigami, this manifestation was fuller and more concrete. Even the Divine Tendrils attaching the Shikigami to Gandharva's body were clearly visible!
[Think of the way the Ten-Tails was connected to Obito back then.]
Shikigami were manifestations of laws, making them almost impossible to sever!
But Yu was not trying to sever the Shikigami's law itself. He was severing the connection between that law and its master!
The physical manifestation of that connection was the Divine Tendril, the weakest link in a Shikigami's law!
Sasori of the Red Sand had once said, "No matter how sturdy a puppet is, its joints are still fragile!"
The same principle applied!
Gandharva had also realized something from this abnormal phenomenon!
"Causal Severance, a Shikigami from beyond the domain. An existence unique even across the seven existing spacetimes..."
Slash! Slash! Slash! The Divine Tendrils were cut one after another, but Yu deliberately left the last one intact.
Once they were completely severed, Amenonakanushi would return to an unclaimed state and vanish into the unseen...
Yu's reasoning was: Among everyone in Mitsuki Country who has awakened the Rinne Sharingan, myself included, none has developed the ocular technique Amenonakanushi. I don't want it falling into the hands of some unknown Ōtsutsuki again...
Yu did not possess the ocular technique Amenonakanushi, so he had no "nest" to house that Shikigami and thus no way to establish a connection with it. Even stripping it away with the Kamui Shikigami would not work!
[Think of when Naruto played tug-of-war with tailed beast chakra to defeat Obito, the Ten-Tails Jinchūriki. Without the Eight-Tails' and One-Tail's chakra, he could not attach himself