The K'ta'viiri were a family or clan within the Althan race, and initially they were most adept with the Essænce. There was mingling among the clans/families, but the K'ta'viiri always considered themselves the master of the Essænce, and this was part of what led to the wars. Think of Sargon from the ST:TOS series. "We dared to think of ourselves as gods."
https://www.youtube.com/watch?v=M4hc7fLQhLo