People are human beings, and we all have to die. However, if bijuu in the People's Column was not sealed to the next person's column before his death, bijuu in the People's Column will leave the People's Column after his death, and return to the natural state because he lost the control of the seal, and exist in this world in the form of a beast. However, some people have a question, that is why this seal was sealed in the body of four generations of Huo Ying Namikaze Minato after his death. In fact, this is because the real powerful person is not Namikaze Minato, and the form of the seal is different, which makes Kyubi no Youko unable to leave after Namikaze Minato's death.
First of all, talk about the real strength of Kyubi no Youko people.
In fact, before Naruto, Kyubi no Youko's last pillar was not Namikaze Minato, but Naruto's mother and Namikaze Minato's wife, "Uzumaki Kushina", who was the real pillar of Kyubi no Youko. In the year when Naruto was born, the Kyubi no Youko seal used to suppress Jiu Si Nai was loosened due to childbirth, so Kyubi no Youko put Jiu Si Nai's body under the control of Uchiha Obito, who took the opportunity to sneak attack, and launched the so-called "Kyubi no Youko Rebellion" against Muye Village.
Later, Namikaze Minato, as the fourth generation Huo Ying of Muye Village, had no choice but to seal the power of Kyubi no Youko's generals in his own body after repelling Uchiha Obito (which is why Namikaze Minato had Kyubi no Youko chakra in his body during the Fourth Endurance World War), but he died because of the sealing technique, but Namikaze Minato died, but the nine tails in his body became even though Bo Feng Shui used that special sealing technique.
Secondly, as mentioned above, Namikaze Minato used special sealing technology to seal Kyubi no Youko, which made Kyubi no Youko unable to escape from Namikaze Minato's body.
This sealing technique is to prohibit the vortex family from "sealing ghosts". According to the introduction of ghost sealing in Naruto, those who use ghost sealing and those who are sealed will eventually be swallowed up by the god of death summoned by seal sealing, and their souls will remain in the belly of the god of death forever. That is to say, although Namikaze Minato was dead, before he died, he put Kyubi no Youko into Namikaze Minato's own body. At the same time, because of the ghost, Kyubi no Youko's power was swallowed up by death together with the soul of Feng Shui Gate. That is to say, although Namikaze Minato and Kyubi no Youko mutually assured destruction, even if Namikaze Minato died, Kyubi no Youko could not break through the seal of death, but stayed in the belly of death forever with Feng Bo Shuimen and became a super-life.