And yeah, Cloud might well have it worst because he's aware of the impending doom, as opposed to 'still walking around in a state of cheerful ignorance,' and yet he's caught between the gotta-be-a-good-guy-reaction of 'she's a harmless little girl, go along with it' and the scrambling-to-salvage-dignity-reaction of 'run away, far away, right now if not sooner.' *fluffles his chocobo-fuzzy head*
Sephiroth doesn't have any idea what Tohru's strike radius (and infection rate) really is. I think he's still trying to cling to his mental badass-image, unaware of the fact that badass may reliably win in mortal-combat but reliably loses to perkycute in everyday-life-with-groceries. :3