I think Graendal is probably one of the most dangerous of the Forsaken - mainly because it is easy to dismiss her as vain and superficial.
Remember, she underwent a radical personality change when she swore to follow the DO - from plain jane ascetic to flamboyant, flashy pleasure seeker. She craves power (all of her "pets" are people who held positions of power). She wants to be Nae'blis because of the power it would give her. She has pulled strings, manipulated others of the Forsaken like chess pieces on a board - hiding her ambitions in plain sight, if you will, by pretending to be exactly what they think she is.
I can't remember the timing exactly but... she had her own private meeting w/ the DO where she was led to believe that she could, very well, be named Nae'blis. I think she must have done something that the DO would want to reward her for - like kill the one who was helping to hone Rand's skills. Asmodean was, by act if not by honest intent, betraying the DO's cause.
I think that Graendal killed Asmodean, went to Shayol Ghul and was rewarded with a "promise". The next Forsaken - Demandred, I think - to go to Shayol Ghul was told that Asmodean was dead, and with details enough to indicate that the killer had told of the deed him/herself.
And another thing... RJ incorporated so much of mythology and the like into his story. "Graendal" is very close to "Grendal". No, Grendal wasn't female - though, the argument could be made that his mother was, at least, as dangerous as Grendal was. Grendal was the thing most feared by all men. It's a play on words/names that I can see RJ utilizing...
Kind of thin, maybe, but that's my theory.
After going through the beginning of LoC, I agree with you completely.
I came to it through different conclusions though, I kind of ignored most of the meeting she had with the DO, and that limited my theory to either Demandred, Semihrage, Greandal, or Mesaana. And then I put out a timeline of what was going on in the book, which only added to it.
Ravhin didn't trust anyone, and so he set wards all around Camelyn to say if anyone channeled, so he didn't trust a lot of the Forsaken in Camelyn, not to mention Rand not coming after him. Another one was, Asmodean knew his killer, so that eliminates a lot of people I had on my list, including Taim, Lanfear (Cyndane), and any of the other reborn Forsaken, how would he have known their new faces?
Also, there's the way he died. No one finds a corpse, no one finds anything really. I think if someone found blood in the palace, Rand would've been informed. Which makes me think it had to be Balefire (Also alluded to in Greandal's meeting with the DO, he said he died the final death), which would leave no blood, and no body.
If it WAS balefire, that eliminates both the remaining male forsaken, Demandred and Sammael. Rand wasn't that far from where Aviendha, Mat and Asmodean were in the garden, and if a male had woven Balefire, Rand more than likely would've felt the power of saidin, and the weave itself, alerting him. Demandred or Sammael probably wouldn't have been that stupid. And they probably didn't use a ter'angreal, as they comment in LoC how none of them has any angreal at all.
That leaves Semirhage, Mesaana and Graendal. The only reason I immediately limit Semirhage and Mesaana is, RJ said with a bit of due diligence, we should know the killer. Semirhage and Mesaana are never really revealed until LoC, and even then I believe no one really owns up to killing Asmodean, or we wouldn't be debating.
So that leaves Graendal. This is supported also because she had a reason to be in Camelyn, her, Sammael, Lanfear and Rahvin were all plotting against Rand, probably to set a trap if he came after Sammael or Rahvin, so that gives her excuse to be there.
Also, in LoC, Sammael notes that Graendal won't expose herself to kill someone, so it's possible that while she was in Camelyn to help Rahvin, or perhaps after he died to be sure of it, Asmodean just stumbled across her (Longshot perhaps), or she was waiting for him. Either way, she seems to be the best bet I have.
*thumbs up for Jacy*
