1. Four-generation Necromancer Seal: When Uchiha Obito launched Kyubi no Youko to attack Konoha, Namikaze Minato used two seals to seal the power of Kyubi no Youko in order to protect the village. Half of Kyubi no Youko's strength was sealed on his son, Naruto Usagi, and the other half was sealed on himself through the Necromancer Seal. The seal of the necromancer is to reach an agreement with ghosts and gods and contribute one's soul to them. Seal each other's souls at the same time, so there is no way for orochimaru to reincarnate Namikaze Minato, because his soul has been sacrificed to ghosts and gods. If you want to be reincarnated as Namikaze Minato, you must first use the endurance of the whirlpool clan to unlock the ghost's seal, otherwise you can't be reincarnated as filth.
2. The power of the fourth generation of Muhuoying: In the early setting of Muhuoying, the strongest Muhuoying was actually the third generation of Muhuoying, but later with the development of the plot, Naruto made corresponding changes, but even so, it is very difficult to face three Muhuoying at a time. In addition, if the fourth generation of Muhuoying Namikaze Minato is successfully summoned, then the fourth generation of Muhuoying must have the power of Kyubi no Youko and the power of Kyubi no Youko. Even three generations of singles are too strong to cope with, so the idea of three generations of singles at this time is not to let one come out. After all, it is good for him to have one less enemy to rely on. First-generation orders, second-generation orders, have made third-generation orders difficult enough. If the fourth-generation order comes out, the third-generation order is estimated to have almost no seal at the end.
3. Three generations of seals: The Vortex clan should be the strongest seal in the whole Huo Ying, but since the Vortex clan was eliminated because of its too strong seal, the seal has not been well continued. The advanced seal of Ghoul Seal should be the unique endurance of Vortex clan, and Namikaze Minato's wife is Xin Jiunai of Vortex clan, so it is not surprising that Namikaze Minato can seal. Then the sealing of the three generations is probably learned from the four generations. When the three generations used the ghost seal, they caught the first generation and the second generation of the target entity. In other words, only by controlling the object that you want to seal can ghosts and gods deprive him of his soul. The art of four generations of flying Raytheon is well-known throughout the forbearance world. It's hard to catch the fourth generation of the target. There is basically no such thing as a seal.
Three generations of Muhuoying is really an admirable Huo Ying, without the resilience of the first and second generations. Faced with virtuous people, they can abdicate in the most difficult period inside and outside the village and come forward. It can be said that the three generations of Muhuoying lived out their lives, got rid of the shadow of the first generation and the second generation, and let Muye Village live a different life. Give the old man a compliment.
I have finished answering. If you have any questions or objections, you can correct them in the comments section.