Aeldari

The Aeldari or the Eldar as they were long known to outsiders, are an ancient and highly advanced species of humanoid xenos whose vast empire once extended the width and breadth of the known galaxy. In its time, the Aeldari Empire was without equal in the galaxy, spreading across both realspace and the Webway. They counted themselves masters of the stars and every Aeldari was born a potent psyker, their abilities often used to both create and power their almost magical technology.

Source

Farseer

Any sufficiently advanced technology is indistinguishable from magic.