Sir Adya was a fictional character from the storybook The Kingdom of Elysian, written by Benny Russell. In the story, Sir Adya was King Ridley's "most loyal and valiant knight," and wielded the sword "Starfall".
When Doctor Joseph M'Benga read the story to his daughter Rukiya, she rooted for an ending in which the characters of Sir Adya and Z'ymira teamed up to defeat the Evil Queen Neve's forces, though in the story they never actually meet.
In 2259, as the USS Enterprise concluded a routine survey mission of the Jonisian Nebula, an entity, later named Debra, brought a version of the story to life from Rukiya's mind, in which Lieutenant Erica Ortegas took on the role of Sir Adya. (SNW: "The Elysian Kingdom")