EWoT:Nisao Dachen is an Aes Sedai of the Yellow Ajah.
She is very short (under five feet) and has an average build for her height. Neither plain nor beautiful, she has dark hair and large dark brown eyes that are her best feature.
She is considered intelligent, even by Romanda. As a Yellow, she is self-assured and thus often unwilling to step back for anyone. 
Strength and Abilities
This is confirmed by "The Wheel of Time Companion" where her level of strength is described as 16(4).
Her area of study is the healing of the mind problems and diseases.
Nisao is 179 years old. She was born in 821 NE in a village south of Kandor on the road to Tar Valon and went to the White Tower in 837 NE. After spending eleven years as a novice and seven years as Accepted, she was raised to the shawl in 855 NE.
She has allied herself with the Salidar Aes Sedai.
Nisao assists Myrelle Berengari in Healing Lan Mandragoran when he arrives, as she is interested in illnesses of the mind. When Egwene and Siuan discovered about this illegal bonding, Myrelle and Nisao are forced to swear fealty to the Amyrlin Seat to escape punishment, thus Nisao is among the first sisters to swear fealty to Egwene al'Vere; subsequently Nisao is acerbic toward Myrelle for involving her in this situation.
Later Nisao is chosen to become a member of Egwene's Council; she had to use whatever influence she had in her Ajah to make sure she was chosen. Nisao and the other Aes Sedai who swore fealty to Egwene are still unsettled about it. Nisao frowns constantly  and the other six do not accept her presence well. She is with Egwene and Gareth Bryne when they survey the area around Tar Valon.
Despite this forced alliance to Egwene, Nisao proved to be loyal to her. She finds the bodies of Anaiya Carel and Setagana, revealing to Egwene that they had been killed with saidin. She also comes to Egwene with the news that Kairen Stang was also found murdered, killed with saidin. Egwene told her to investigate discretely about it.
In fact she comes to seek a meeting with Romanda Cassin. She tells Romanda that Lelaine has forbidden her to carry on investigating the deaths of both Kairen and Anaiya, citing that it is Blue Ajah business. But Nisao complained that she was charged by Egwene to investigate those murders and Romanda gives her permission to carry on looking for the murderer.
Black Tower delegation
Somehow Lelaine (with probably some aid from Sheriam Bayanar) finds a way to send away several sisters sworn to Egwene.
In fact Nisao, Myrelle, Theodrin Dabei and Faolain Orande are part of the delegation sent to the Black Tower and has not been heard from them in some time. This is a very strange choice to send Nisao because she has a Warder. Strange choices also for Theodrin and Faolain that are not recognised full sisters from the majority of the rebels. Egwene wonders if someone was purposely sending away many of her supporters.
It is presumed she survived the Last Battle.
- ↑ 1.0 1.1 Crossroads of Twilight, Chapter 16
- ↑ 2.0 2.1 A Crown of Swords, Chapter 12
- ↑ 3.0 3.1 Crossroads of Twilight, Chapter 20
- ↑ Lord of Chaos, Chapter 8
- ↑ Lord of Chaos, Chapter 30
- ↑ A Crown of Swords, Chapter 16
- ↑ Crossroads of Twilight, Chapter 30
- ↑ Knife of Dreams, Chapter 23
- ↑ The Gathering Storm, Chapter 45