I agree it was Graendal. There was one other clue besides the one you mentioned. When the gateway opens Graendal immediately knows it is Moridin. If she had any doubt about Asmodean being alive, she wouldn't be sure it was Moridin. Of the men, only Sammael, Asmodean, and Moridin knew her location. She is certain Sammael and Asmodean are out of the picture and the gateway must have been Moridin. Graendal killed Asmodean...it's obvious.



Some of Graendal's thoughts shed more light. Particularly her thoughts about Semirhage vs. Demandred vs. Mesaana. These thoughts I do not doubt and I agree that Semirhage and Demandred are pretty much on an equal playing field. Mesaana clearly seems weaker in Graendal's opinion. Before we jump to the conclusion that Mesaana is weaker in the power though, we need to realize that Graendal's thoughts could have been implying much more than just one power strength. I think Graendal was looking at one's ability to manipulate others, control events, etc. It very well could be that Mesaana is just as strong of a channeler as the others, but that she lacks the political maneuvering skills of Demandred and Semirhage.

Also, now that Graendal has an angreal, any statements regarding how she would do against the others have to be scrutinized closely. Of course Graendal's confidence in her ability to confront the other Chosen is boosted. She has an angreal. Without her angreal she might be expressing different opinions about her own ability to confront the others.

I wouldn't call Graendal exactly afraid of Demandred or Semirhage. But there's no doubt that she wonders whether she could take either of them out. I think this is the best evidence so far that Demandred and Semirhage are more powerful than Graendal. Simply put, even with the angreal's boost in strength, Graendal thinks it an even match between her and Demandred or her and Semirhage. That says a lot.



There's no way to know at this point.



That is one of the most astute observations I've seen so far. I never considered that Rand's madness might not be from the taint on saidin, but could have come from Moridin. That's worthy of deep thoughts.

Lanfear