For some reason, Ryobu always felt that he had yet to completely tame the Dragon Vein. He was merely using the Rinnegan's power to suppress the Dragon Vein's Chakra and make it serve him.
He had not truly tamed it. Once Ryobu severed his connection to the Dragon Vein's Chakra, the Dragon Vein would go berserk.
Ryobu felt that the key to the problem lay with Sara.
The Sara Clan's bloodline could control the Dragon Vein, whereas Ryobu did not possess the Sara Clan's bloodline.
He could only defeat Minato and the others first, then find an opportunity to make use of Sara.
All of Ryobu's Chakra gathered toward the Rinnegan on his forehead.
The Six-Tails cried out in terror, "This is bad! Uchiha Ryobu is going to use a Rinnegan Dojutsu! Mei Terumi, stop him!"
How was she supposed to stop him?
Mei Terumi was only about the same age as Kakashi and Obito right now. At present, she was not yet the Mizukage from the Original Work.
Being able to exchange a couple of moves with Ryobu already made her an exceptional young prodigy.
And she wanted to stop Ryobu's Rinnegan Dojutsu?
Dream on!
Mei Terumi and the Six-Tails turned to flee.
But Ryobu's Rinnegan suddenly locked onto the eyes of the Six-Tails and Mei Terumi.
With just one glance—only one glance—the Six-Tails was controlled by the Rinnegan's Illusion Technique, and Mei Terumi was controlled as well.
In the Original Work, Sasuke's Six-Tomoe Rinnegan had controlled the Nine Great Tailed Beasts with a single look.
The Rinnegan's Illusion Technique was an overwhelming, one-sided blow against Tailed Beasts. If even Tailed Beasts could be controlled, then frail humans went without saying.
Only after the acidic mist dispersed could Kushina and the others clearly see the state of the battle