Gaius being the PS would make a lot of sense, really. He manipulates the rebel guided, then kills them. He leads Kalmar to believe he is being controlled, and it has worked. Everyone thinks he's a rebel. I was thinking Gaius could be Tetzel, have god-like powers - like being able to 'reconsider' a wanderer's position on the way, and sensing. He may be some sort of super-human, and he thinks it gives him the right to judge what is right, and what is wrong, he may be the book of sermot and eve too. It's clear that he does know Rhue has done something with him, and he doesn't want Rhue to remember. Maybe now that he knows Rhue can't remember, Rhue can no longer expose the truth. I know this has been discussed before, but maybe he has two auras? One is afraid the other will manipulate the powers he has, the other kills rarely. Gaius could truely believe that Rhue is the PS, and doesn't realise that he, himself has become what he always dispised.
I know most people have theoried Gaius = Perfect blade, but I think he couldn't be manipulated by anyone at all, he's the brain behind the Rebels, and the brain that stopped them too
"Something's eating in to.. my head!" Rhue did this to Slade.. didn't he? I've seen Gaius look in to people's minds, but Rhue and Kalmar seem to be able to actually talk to them there?