When Yu Xu traveled through the world of Naruto, he was stuffed with all the chakra from One-Tail to Nine-Tails at the beginning. His physical body was on the verge of collapse, and he had a three-day countdown to the chakra rampage.
While others contracted with psychic beasts, he directly contracted with tailed beasts - using the liquidated damages clause of modern legal contracts, he tied the Nine-Tails, which had been filled with resentment for thousands of years, to the chariot. If he violated the contract, his chakra would be deducted. Nine-Tails had never suffered such grievances in the workplace.
When Payne was attacking and Konoye Village was in despair, the phantoms of the nine tailed beasts appeared behind Yu Xu: "I'm sorry, I am the only one who can fight my client."
Not enough chakra? Come and get a contract. Starting from Naruto, every tailed beast was signed as a lifelong employee, and the style of the ninja world collapsed.
