Lethean

The Letheans are a telepathic species, whose telepathic attacks are almost always fatal. Their skills led them to being hired by various criminal groups in the 24th century. They are known for being incredibly stubborn.

History
In the 23rd century, the Lethean flag-ship was supposed to meet the USS Enterprise (NCC-1701) for an official first contact but they never arrived. Instead, the flag-ship was accidentally met with the USS Phoenix-X and the USS Atlantis from the future-- ruining their perception of the Federation. During this encounter, a part of the Atlantis` starship technology, an interface module, had been broken off whilst in mid-battle with the Phoenix-X. The module was retrieved by the Lethean before both future ships disappeared into the space-time continuum.

This future technology had a big influence on Lethean culture since the interface module was related to the Neural Command Interface.
 * It is possible the technology was somehow adapted and able to further the Lethean's telepathic ability over the course of the century.

In an alternate timeline, in the 26th century, the Lethean had become "super-telepathic", to the point of telekinesis.

When met with the time-travelling Phoenix-X in this period, the Captain of the Lethean vessel Mikonikoff, was able to force the Phoenix-X crew to thier knees by a single thought.

However, by this time, Starfleet still has a hold over the Lethean. What ever technology advances the Lethean had in this century, was by no means comparable to Starfleet. Despite the telekentic ability, the Lethean feared Starfleet.
 * It may be possible that Starfleet has derived some kind of shield against telekinetic attack in the 26th century.

Appearances

 * "Temporal Doom! Part II
 * "Temporal Doom! Part II