[ And we all know what advice Sephiroth would give. ]

One of the other gods indicated that if we answer these prayers, we will likely encounter them. [ In retrospect, Sephiroth should have asked Sora for more detail, but at the time he'd had more than his fill of people in general. ] If they touch you they can make you sick; Blight they call it.

[ And they'd also said that Sephiroth's emotion could possibly do the same thing. Upon the heels of that thought, he looks back at Zack. ]