Simply because madara won't have a pet to destroy anything anymore. Madara waited a long time just so he can get the power of the nine tail demon fox again.
This is why minato sealed the nine tail demon fox into naruto and also because naruto's grandmother and mother were host of the nine tail demon fox. Who better than naruto to be the perfect host of the nine tail demon fox. With this minato was able to still maintain the power of the nine tail demon fox in konoha's possession. Every big nation had one, it would be dangerous if konoha lost the most powerful tailed demon.
Do you honestly think that naruto can defeat madara even if naruto has now control of the nine tail demon fox? Naruto needs something more special than this in order to defeat madara. This is why minato just said that he hoped he would use the power of the nine tail demon fox.
I told you, as long as the Shinigami works your will, everything goes as planned. Even the Nine-Tails is no match for the death god
what makes you think this?
my assumption to whether minato was able to use a suppressing seal against the nine tail demon fox will come soon. I am not trying to make you believe my assumption but you are trying to say that my assumption has no way to be right which it's wrong.
Tell me, when will your assumption be proven right or wrong?
everyone respects the power of the nine tail demon fox which makes it even harder for minato to seal it into his son
You said that madara + nine tail demon fox would take him seconds to defeat minato. Now you are saying that it would take him time to defeat minato even with the nine tail demon fox aiding him.
which one do you want me to believe you?
You didn't pay attention to any of the evidence I just presented to you. If the special power wasn't the Nine-Tails, then why didn't Minato just seal the Nine-Tails into himself, killing himself along with the beast? That way, there is no chance that Madara will ever retrieve the fox. The "special power" Minato spoke of
is the Nine-Tails; otherwise, Minato would have no reason to seal it into Naruto, when he could just kill the beast by sealing it into himself. It doesn't matter if Konoha loses the Nine-Tails; at least Madara will never be able to get his hands on it again.
By the way, Naruto's grandmother has never been shown in the story, and if you think Mito Uzumaki is his grandmother, then you are completely wrong.
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Kushina tells Naruto that Mito was simply her predecessor, not her mother. I don't know where you got the idea that Mito was Naruto's grandmother, but in any case, you are incorrect. It still doesn't matter if Kushina and Mito were former hosts of the Nine-Tails; what matters is that the "special power" is the Nine-Tailed Fox,
and that was why Minato chose to seal it into Naruto. It would not be the end of Konoha if they lost the Nine-Tails; Madara would never be able to retrieve his most powerful weapon ever again.
Minato hoped Naruto would be able to use the Nine-Tailed Fox's power to defeat Madara. I don't know what sort of techniques Naruto will be able to perform now that he has full control of the Nine-Tails, but they all go towards Naruto defeating Madara. That was what Minato had in mand when sealing the Nine-Tails into his son.
And again you don't pay attention to the evidence I showed you. You just asked what made me think the Shinigami is essentially able to do anything, as long as it is working your will?
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To reiterate, look at what Orochimaru says: "you mean that this was the jutsu that sealed even the Kyuubi?!" If Minato called upon the Shinigami to seal the Nine-Tailed Fox, then that is what it would do.
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You want me to believe that Minato used a suppressing seal against the Nine-Tailed Fox, but you have not provided one iota of evidence to support your statements. What do you want me to believe? Something that is based purely on opinion?
And when did I say it would take Madara, alongside the Nine-Tailed Fox, an extensive amount of time to defeat Minato? I said that he would be defeated quickly, because Minato, without Mokuton techniques, could do nothing against the fox and consequently would be defeated rather easily. The best he could do is run away with his Flying Thunder God technique. Madara would just be too powerful; everyone in the Naruto world is aware of his immense strength.
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