One of the only matchups that Itachi loses. He gets overwhelmed by Tendo and his stamina pool isn't large enough to drag the fight against 6 different bodies. Sharingan genjutsu should be extremely limited here too.
Fighting Nagato instead of the paths would better his chances actually.
I agree that Sick Itachi loses but I’m assuming you have Edo Itachi over Pain right? Since those stamina and chakra issues are gone.
Also, I wanna push back on the Genjutsu resistance thing. It’s never said that Rinnegan has Genjutsu resistance, this is simply a Mandela effect that the fanbase has gaslighted itself into. Just because it’s a superior eye doesn’t mean it’s immune to everything the inferior eyes has below it. Especially not MS level Genjutsu. The only statement regarding this matter is Sasuke’s Rinnegan’s resistance to the Infinite Tsukuyomi BUT Sasuke had his Rinnegan amped up by his own EMS and Six Paths chakra. Nagato’s Rinnegan is fodder in comparison.
Itachi can definitely use Genjutsu against Pain. Worst case scenario, he’ll be forced to use Tsukuyomi but it can canonically land on multiple targets at once so it shouldn’t be an issue.
Tldr, most paths outside of Deva and Asura is fodder to Itachi. Asura can also be defeated by Totsuka Blade GG “easily” (easily is in quotations because while Itachi’s arsenal does have a very viable wincon against Asura, I wouldn’t say him using his strongest weapon is easy).
Deva is the only problem.