[The snap of the pen being capped seems to dictate the way that Sephiroth blinks and looks away around them again, as if putting a cap on his own sometimes overbearing attentiveness towards others. Was it all innocent til proven guilty, or the other way around which should be the logical thought train here?]

It certainly seems to make sense for there to be more than one culprit, either that or we're dealing with a highly skilled wielder of several jobs who probably had a job switch implemented as part of his -or her- plan.

[That latter concept is enough to make any of them shudder; is there someone among them who could be so coldly calculative?]

...if it's even a Hero of Light, and not some other type of foe we've yet to encounter. I dislike either possibility, as I'm sure you do too.