One major argument I've seen for Itachi in MANY vs threads has been his ability to use Izanami. I'll explain why this is a major misconception, and Izanami is waaaaaaayyyyyyyyyy more difficult to use in battle than people seem to believe.
So lets do a brief explanation on Izanami.
Basically what Itachi is saying is that in order to use Izanami, he must perfectly repeat a sensation shared between he and his opponent. This means that the genjutsu itself does not begin until the sensation has successfully been repeated a second time.
What does this mean? Well, this means that versatility in battle makes Izanami's effectiveness very low, as it would be incredibly difficult to have an exact sensation be repeated if the opponent is attacking in a different way each time. It also means that even when he activates Izanami, he still has to stay alive until he can replicate the specific sensation again. In this time, he can also die (so when he got cut in half against Kabuto, that was for real).
This also means that Itachi has to create a specific sensation that he and his opponent share WITHOUT DYING. In a fair battle, the first time he got stabbed by Kabuto would have been the end. And this is harder than one would think, especially considering the power of the ninja that Itachi is compared to. Most of them, if allowed close enough to share a sensation with, would be able to kill him. So we have another reason that Izanami is not very useful in battle.
Finally, the last weakness of Izanami is that it only works with overly arrogant or overly stupid (procrastinatory) characters, as explained here.
Once a character acknowledges their results, the genjutsu is broken. This means it can be broken quickly by characters who aren't so arrogant or stupid. And if they break out of it quickly enough, they will be up against an Itachi who no longer has one of his eyes. It is an incredibly risky battle strategy, and Itachi only used it against Kabuto because he saw how arrogant Kabuto was, and knew Kabuto would be stuck for a while.
So all in all, Izanami is not the be all end all of combat moves. In fact, it is very unlikely to be used in battle due to the circumstances necessary to activate it, and even if he somehow manages to do so, there are many ninja who can break it quickly, and so it would not be tactically useful in that situation as well.
So the moral of this story is STOP OVERRATING THIS JUTSU.
So lets do a brief explanation on Izanami.
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Basically what Itachi is saying is that in order to use Izanami, he must perfectly repeat a sensation shared between he and his opponent. This means that the genjutsu itself does not begin until the sensation has successfully been repeated a second time.
What does this mean? Well, this means that versatility in battle makes Izanami's effectiveness very low, as it would be incredibly difficult to have an exact sensation be repeated if the opponent is attacking in a different way each time. It also means that even when he activates Izanami, he still has to stay alive until he can replicate the specific sensation again. In this time, he can also die (so when he got cut in half against Kabuto, that was for real).
This also means that Itachi has to create a specific sensation that he and his opponent share WITHOUT DYING. In a fair battle, the first time he got stabbed by Kabuto would have been the end. And this is harder than one would think, especially considering the power of the ninja that Itachi is compared to. Most of them, if allowed close enough to share a sensation with, would be able to kill him. So we have another reason that Izanami is not very useful in battle.
Finally, the last weakness of Izanami is that it only works with overly arrogant or overly stupid (procrastinatory) characters, as explained here.
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Once a character acknowledges their results, the genjutsu is broken. This means it can be broken quickly by characters who aren't so arrogant or stupid. And if they break out of it quickly enough, they will be up against an Itachi who no longer has one of his eyes. It is an incredibly risky battle strategy, and Itachi only used it against Kabuto because he saw how arrogant Kabuto was, and knew Kabuto would be stuck for a while.
So all in all, Izanami is not the be all end all of combat moves. In fact, it is very unlikely to be used in battle due to the circumstances necessary to activate it, and even if he somehow manages to do so, there are many ninja who can break it quickly, and so it would not be tactically useful in that situation as well.
So the moral of this story is STOP OVERRATING THIS JUTSU.