Gedo is powerful, but an easy target. Totsuka blade one shot seal. Amaterasu one shot burned.
Gedou Mazo can create shockwaves. Itachi tries to get close to strike it with Totsuka, Mazou punches the ground, creating a shockwave that makes him lose his balance and footing, effectively cutting off Itachi's ability to move around. At the same time, Deva creates Chibaku Tensei and launches it into the air. Itachi is distracted, and can't stop the gravity orb. Chibaku Tensei is done game for him.
Chibaku tensei. It is unknown whether or not his long rage move by its self could have destroyed it, but it is possible. Regardless if he knows about chibaku tensei, he won't get allow him to do it.
Same scenario above. As for whether or not the Magatama could have destroyed it, consider this, the Chibaku orb was capable of holding what has to be billions of tons on it. Since the orb emits a powerful force of gravity, that means all that weight is constantly pushing pressure down on it. No Magatama is destroying that orb. Nothing Itachi has can destroy it.
Asura path is nothing, Itachi is able to move extremely quickly and can dodge the most intense attacks easily.
Not if Asura launches all of those bombs at Itachi. While Itachi is defending against that, the other Paths or summons can strike him. Or, Chibaku Tensei.
Large scale shinra tensei leaves the deva path unusable for a certain length of time. Blocks it with yata mirror and makes him waste it.
Who said Pein will launch the large scale right away? Nothing's stopping the Animal Path and Asura path from launching constant barrages of attacks on Itachi. Birds dive at Itachi, Cerebrus dogs attacking at him, Asura launching bombs and lasers constantly, Itachi needs to keep up Susano'o to survive. And he can't keep that up for too long, a few minutes and he's done. Then, boom, Shinra Tensei turns Itachi into a bloody mess under tons of rubble. Shit, even a mid-sized Shinra Tensei like what Pein did to Kaashi before the nail attack would suffice.
Birrage of summons? Totsuka sword seals them or he fodderizes the summons like he did in the fight with nagato.
Totsuka doesn't seal instantly and Pein can launch multiple large animals at once. The ram would charge and Itachi, Itachi stabs it with Totsuka. As we've seen with the sealing of Oro's Eight Branches and seen Nagato, the sealing process is slow, which allows the other summons like rhinos, birds, dogs and bull to safely and openly attack Itachi.
You tell me how Nagato will get past all of Itacih's genjutsu, sussano with yata mirror+totsuka sword+magatama, and amaterasu.
Shinra Tensei pushes Itachi back until he loses stamina for Susano'o, which is a few minutes. Shinra Tensei and Preta Path handle Amaterasu and Magatama. As for Genjutsu, all the Peins' chakra are connected. Meaning if one is in Genjutsu, Deva Path can expel a Shinra Tensei. This will push Itachi back, as well as release all Peins from Genjutsu since the expulsion of chakra will disrupt and expel Itachi's Genjutsu-causing chakra.
Amaterasu immediately takes out 4 of the six paths of pain. The only ones that can survive it are preta path and deva path (if he can use shinra tensei to blow them away before hes burnt), while preta path is absorbing it, totsuka sword. Boom down to 1 left. And the deva path who is extremely badly burned is nothing in front of the eyes of Itachi.
Once again no. Preta Path handles it. Also, Nagato can sense Amaterasu coming. Nagato would just launch an attack at Itachi, such as Asura bombs or Summons, that will force Itachi to redirect his Amaterasu. That's a shot wasted that will probably cause Itachi enough discomfort to grab his eye and shrink down a bit, leaving him open to an attack or for Pein to activate Chibaku Tensei.