I've noticed quite a few NB users having the misconception that Orochimaru is weak against genjutsu, mainly due to his encounter with Itachi. However, this isn't the case at all. Firstly, I would like to point out the Orochimaru has a 5 in the databook, in both genjutsu and intelligence. Now, I mention intelligence because genjutsu is most often used by ninja with very precise chakra control and very high intelligence.
Here; we see both Itachi and Orochimaru have a 5 in both;
With Itachi, there no secret that he is a prodigy and arguably the best genjutsu-user in the Manga. Therefore, making his genjutsu the strongest/hardest to break, apart from Shisui Uchiha's.
Now, the incident that occurred (between Itachi and Orochimaru) wasn't fully shown in the manga, all we know is that Itachi and Orochimaru were face-to-face and Itachi had him in genjutsu.
That ultimately lead to Itachi cutting Orochimaru's hand.
For those of you don't know, Itachi used binding genjutsu. This is suppose to prevent its victim from moving COMPLETELY, making this probably the hardest techniques to break.
However, Orochimaru was able to do exactly that!!! Orochimaru not only was able to move after being put in binding gnejutsu against the best user in the series, but even made the attempt to break it. Itachi knew that Orochimaru wasnt one to take lightly and was aware of the fact that he could break sharingan genjutsu, as he rushed over to Orochimaru to prevent this from happening.
As shown in this image, notice distance between Itachi and Orochimaru;
Orochimaru not only *chuckles* at being in the situation and attempts to break it, but forces Itachi to closed the distance quickly and cut off Orochimaru's hand.
If there was more distance, Orochimaru would have broken/release this jutsu rather easily and Itachi knew this. Hence, Orochimaru is NOT weak against genjutus, he simply tends to underestimate its ability xd cocky bastard



Here; we see both Itachi and Orochimaru have a 5 in both;
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With Itachi, there no secret that he is a prodigy and arguably the best genjutsu-user in the Manga. Therefore, making his genjutsu the strongest/hardest to break, apart from Shisui Uchiha's.
Now, the incident that occurred (between Itachi and Orochimaru) wasn't fully shown in the manga, all we know is that Itachi and Orochimaru were face-to-face and Itachi had him in genjutsu.
You must be registered for see images
That ultimately lead to Itachi cutting Orochimaru's hand.
You must be registered for see images
For those of you don't know, Itachi used binding genjutsu. This is suppose to prevent its victim from moving COMPLETELY, making this probably the hardest techniques to break.
You must be registered for see images
However, Orochimaru was able to do exactly that!!! Orochimaru not only was able to move after being put in binding gnejutsu against the best user in the series, but even made the attempt to break it. Itachi knew that Orochimaru wasnt one to take lightly and was aware of the fact that he could break sharingan genjutsu, as he rushed over to Orochimaru to prevent this from happening.
As shown in this image, notice distance between Itachi and Orochimaru;
You must be registered for see images
Orochimaru not only *chuckles* at being in the situation and attempts to break it, but forces Itachi to closed the distance quickly and cut off Orochimaru's hand.
If there was more distance, Orochimaru would have broken/release this jutsu rather easily and Itachi knew this. Hence, Orochimaru is NOT weak against genjutus, he simply tends to underestimate its ability xd cocky bastard