Biographical information
Gender Female
Status Dead
Abilities Unknown
Occupation Unknown
Appears in Words of Radiance (mentioned)

Madasa is obviously a historical person in The Stormlight Archive. Presumed to be female, given 'her' name, 'she' is mentioned only in the Epigraph for Words of Radiance: Chapter 44.

But as for the Bondsmiths, they had members only three, which number was not uncommon for them; nor did they seek to increase this by great bounds, for during the times of Madasa, only one of their order was in continual accompaniment to Urithiru and its thrones. Their spren were understood to be specific, and to persuade them to grow to the magnitude of the other orders was seen as seditious.

–From Words of Radiance, chapter 16, page 14[1]


So, Madasa was a ... leader of sorts?