I've read a theory somewhere on the Net that Moiraine and Lanfear might come back from the doorway ter'angreal as a mixture of the two people. And when you look at Cyndane (the 'girl' who was stronger than Graendal in the OP who accompanied Moggy to Graendal's palace): 1. Her height (short) and the way the holds herself (upright so as to gain every hair of height she can) implies Moiraine very strongly 2. The eye-colour (blue) matches with Moi's 3. I'm assuming that the only person (other than a Forsaken) who's an even match for Graendy is Nynaeve, and she'd rather be stilled and dead than partner with Moggy. So therefore that only leaves one of the other Forsaken, especially since Cyndane is STRONGER in the OP than Graendy. 4. The name Cyndane ('Last Chance' in the Old Tongue) seems to somehow fit with Moiraine and Lanfear's situation but I can't quite put my finger on it yet.