And how do you figure that? His mind was proven to be susceptible to suggestion very easily throughout all of FF7. Sephiroth used his weak mind to control him (along with the Jenova cells in his body), he mutated his own memories into a false history and was constantly having flashbacks and fragmentation of his consciousness. Sephiroth's ability to screw with his mind is proof enough that he is very vulnerable to mental attacks.
Hybrid Mode
