Activities and Death
After Demandred founded the Eighty and One, he confronted Lews Therin Telamon in battle. Tellindal was present and was struck by a lightning from the sky. Lews Therin apparently watched her die with her blood on his hands. It is not clarified properly that her death was caused by LTT despite that a prophecy, passed by Arafelan monarch to monarch says so.
Tillendal is mentioned in a foretelling given by an Aes Sedai of King Paitar Nachiman's own family line. When the Dragon is reborn, the Borderland kings and queens must travel to him and question him for knowledge about how Tellindal died. If the Dragon Reborn answers correctly, they will follow him, but if he does not, they must strike him down on the spot so that the Light might not be consumed by whom who was to have preserved it.
Although in TOM the character is referred as a female character, in The Wheel of Time Companion book the person is referred as male character. "He was killed in an attack by Demandred." It is not confirmed that LTT killed her/him.