Yes, Reincarnation Justu.
This was the second step of Chiba's plan—and the final one.
The step that would absolutely ensure the survival of those he wanted to save! After the battles before the Night of the Nine-Tails, after coming into contact with Uchiha Nobuhiko, Chiba had already realized that Kushina and Minato Namikaze were likely beyond saving! Kushina and Minato Namikaze were doomed to die.
He had realized it back when Uchiha Nobuhiko stole his transmigrator power, when he fell unconscious and entered the mental space.
At that time, Kushina and Minato Namikaze's fates had already been decided.
The moment he failed to defeat Uchiha Nobuhiko immediately, it had been decided.
Minato Namikaze and Kushina were doomed to die.
If he had been able to defeat Uchiha Nobuhiko earlier, then perhaps there would have been a chance to save Kushina and Minato Namikaze.
No! More accurately, there would have been a very high chance.
The greatest obstacle to Chiba changing Kushina and Minato Namikaze's fate on this Night of the Nine-Tails had never truly been Uchiha Obito. It was Uchiha Nobuhiko. As long as Uchiha Nobuhiko was defeated at the right time, Uchiha Obito would have been nothing to worry about.
In fact, Uchiha Obito had not posed a fatal threat to Minato Namikaze in the original story. Minato Namikaze died entirely because of the Nine-Tails.
He fought the tailed beast, and in the end, because he lacked Chakra and for other reasons, he could only stake his life on sealing the Nine-Tails.
To save Minato Namikaze and Kushina, all Chiba had needed to do was stand by their side and assist Minato Namikaze in sealing the Nine-Tails when they did so.
With Chiba's Sealing Jutsu working alongside Minato Namikaze's—or with Chiba restraining the Nine-Tails—Minato Namikaze would not have needed