Lanfear
Known as Mierin before going over to the Shadow, Lanfear was second in power only to Ishamael. Obsessed with Lews Therin, she made many futile attempts to win him from his wife. When she was freed from Shayol Ghul, she first went to Rand, thinking he was as close to Lews Therin as she would ever get. She found him first using the Portal Stone, calling herself Selene. They were separated, and later Rand found out her real identity. In Cairhien, Lanfear returned, and tried to kill Rand, Egwene and Aviendha for trying to take Rand away from her. Moraine gave her life to save them, by throwing herself and Lanfear into the twisted doorframe, which subsequently melted. A current idea is that the two are not dead, but trapped in the ter'angreal. A dream that Egwene had was of Thom pulling Moraine's blue stone out of a fire, and Min had a viewing that Rand couldn't win without Moraine. Lanfear may still be roaming around the world too.