Why didn't the four generations of Naruto recognize the masked man in the Kyubi no Youko incident? In fact, according to the normal logic of the plot development, the skills used after the blackening of the soil and the change of personality, it is difficult for Namikaze Minato to identify the soil, which is explained in detail below.
According to the early plot of Huo Ying, Namikaze Minato thought that Daitu had died trying to save Kakashi in the Third Endurance World War, and he didn't know about uchiha madara's rescue of Daitu.
The plot route in the early stage of Huoying is relatively clear, and both the villain and the villain have their own unique plot development context.
According to the normal development direction of the plot, Uchiha Obito's act of saving Kakashi in the Third Endurance World War was considered as a sacrifice by the ninja in Muye Village. Namikaze Minato could not have a God perspective like the audience, knowing that uchiha madara pulled the soil into the water in order to realize his own plan, and designed to blacken the soil successfully.
Therefore, even if Tui appeared as a masked man in the Kyubi no Youko incident, Namikaze Minato could not associate Tui's image with the masked man now. After all, all aspects have changed greatly since Tui was blackened.
Namikaze Minato, to put it bluntly, doesn't know much about Tui, but he's just a lead teacher arranged after he graduated from Ninja School. The follow-up time is not too long, and the problem of the Third Enduring World War makes Namikaze Minato's understanding of bringing soil exist in his previous personal image. Naturally, it is impossible to easily identify Uchiha Obito as a masked man.
Namikaze Minato and Daitu didn't go through a long cognitive process. The relationship between them started with a ninja school graduate and a team leader.
In fact, because the existence of Watergate class is not too long, it is impossible for Feng Shui men to clearly understand the characteristics of soil, and the appearance characteristics and personality characteristics of masked men in subsequent plots are very different from those recognized by Watergate.
therefore, it is understandable that you can't identify the soil.
In addition, in the normal plot trend, Daitu is thought to have been sacrificed in the mission of the Third World War. According to the thinking of ordinary people, it is naturally not thought that Daitu has a chance to continue to live, including Namikaze Minato, and the characters in Huoying cannot be omniscient and omnipotent.
In the Kyubi no Youko attack, Tu Tu, a masked man, didn't use the fighting skills he was good at before, which made it difficult for Namikaze Minato to search for clues about Tu Tu.
The skills used by Tui in the Kyubi no Youko attack basically exceeded Watergate's cognition of Tui in his school days. The combat skills mastered by Tui before the blackening had obvious characteristics of Uchihiro clan, such as being good at using fire escape.
However, at the stage of controlling Kyubi no Youko's attack on Muye Village, the skills used by Tui are Shenwei+Magic+Psychic, which is quite different from the previous Tui.
With such obvious differences in skills, it is impossible for Namikaze Minato to detect all the characteristics of the masked man through a short fight.
The kaleidoscope sharingan was not turned on when Tui was in the Watergate class, so Watergate didn't know that Shenwei was the exclusive skill of Tui sharingan. Even if the masked man used the space transfer ability many times in the battle, it was difficult for Watergate to connect Tui with the masked man. Moreover, in order to avoid being discovered, we should try to avoid using the unique ninja skills of Uchihiro clan.
As for the situation that the masked man knows the attack mode of Watergate, since Namikaze Minato became famous in the Third Endurance World War, basically other ninja villages have studied the style of Watergate. Therefore, it is very difficult for Watergate to rely on the masked man's understanding of himself to recognize the soil.
The difference between the combat skills of the masked man and the soil that Watergate recognized is very obvious, and Watergate doesn't know that the soil that opened the kaleidoscope in the later period can use special space transfer ability, so naturally he won't think that a dead character in his impression is the real identity of the masked man.
To sum up, personally, it's not complicated that Watergate can't identify the masked man with soil. On the one hand, Watergate thinks that the soil has died in the world war. On the other hand, the fighting skills with soil after blackening are very different from what Watergate knows, which makes it difficult for Namikaze Minato to identify the characteristics of the soil from the short-term fight with the masked man. Please forgive me if the analysis is not in place. Please leave a message for discussion if you have other ideas.