Hi, sorry to bother, but you were listed among the Knowledgeable Members of Final Fantasy. I've been wondering for a while. In his profile, Sephy has listed the ability to strike souls. When did he use or was mentioned to have said ability? Need to know, because we're discussing a matchup and depending on whether Sephy can or not attack souls can really alter the veredict.
But also, it's likely it also has something to do with the materia and the lifestream, since i do remember some talk about souls in it, but i can't help you there since it's been a while since i saw the plot of FF7, sorry.