You aren't reading my posts, Roo-kun. I never said genjutsu in general doesn't work. I even confirmed it in my previous post. And you must've skipped pre-skip to not know that sharingan powers resist ocular genjutsu:
Kakashi uses borrowed eyes, and he confirms he can fight off regular Sharingan genjustu. Itachi confirms that If you have a Sharingan, you can resist genjutsu even from an upgraded eye i.e., MS. Basically, even if you're not an original user, an inferior ocular jutsu can resist a superior jutsu. Sasuke, being a pure Uchiha, could even see through Itachi's Tsukuyomi despite lacking MS.
My argument here is about a far superior eye resisting a far inferior eye. Exactly the reverse of what happened with Itachi and Kakashi. What's more, Nagato is of Senju blood so his abilities aren't as degraded as Kakashi's. We already got a confirmation via Sasuke, and no, Zetsu is surprised because he could resist even "Infinite Tsukuyomi" because it's the ultimate genjutsu. He's not surprised that Sasuke can resist genjutsu in general.
Once again, it's not about Nagato or him having genjutsu resistance in general. It's about a regular Sharingan genjutsu vs rinnegan here lmao. Rinnegan isn't a separate eye, it's literally an upgraded Sharingan, period.
Obito controlled a perfect Jinchuriki, and that's why I said his genjutsu is by far the most impressive for a Sharingan user but it's nothing like Koto or even Tsukuyomi for that matter. Ao never said it's similar to Koto. He just talks about how he's able to see through the deception, and by extinction, the genjutsu. Ao literally fought and survived Shisui.
This proves nothing as far as it concerns how an ocular jutsu affects a superior eye because we know for a fact that ocular powers could resist ocular illusions.