U'lanna

The U'lanna was a Beta Quadrant species long extinct. It possessed psionic technology allowing one to control the will of others. 

It was ruled by the U'lanna Commonwealth; the species was extinct 3,000 years ago because of a supernova. Also, the species was in the middle of a civil war at the time of extinction, with the U'lanna Rebel Alliance extant at that time. The race was notorious for shunning deflector shields.