This doesn't really work - Ultra's came claim after Charles', so all it really does is prevent the dichotomy between "one of Charles and SK is lying". Now if Charles is scum this could maybe be revisited, but they would have to be exactly scum together. And then we analyse Charles countering SoulKiller - there was no real need to do this as Soul's census claim was doing nothing. I don't see plausible scum motivation here at all.