The Psilons are a race of beings that prize intelligence above all else, and while they were able to develop advanced technology, they didn't have the courage to use it. The Mrrshan used this to their advantage in the Mrrshan-Psilon war over 3,000 cycles ago. The Psilons have long since been assimilated into Mrrshan culture and are the driving force behind the majority of the Mrrshan technological endeavors. Since the Psilons have been a part of Mrrshan culture for so long, they are treated almost as equals, and while they rarely are ranking military officers on Mrrshan starships, they do serve as tech and science officers on most Mrrshan ships.

The Psilons live on any planet that is not suitable for industrial production, in addition to Orion II, which has a multitude of ancient artifacts for research. The largest concentration of psilons, is however, in the Al'dev system, where the Mrrshan develop new and advanced weapons.

The Psilons are a decidedly weak species, when compared to most others. They originally came from a low-gravity planet, and they only have one heart, and singular organs. Because of this, they are weak when placed on a planet with normal gravity, and they simply cannot do anything on planets with high gravity. To combat this, the Psilons wear advanced power suits with an antigravity generator when serving on ships and planets without the benefit of a localized gravity generator. While Psilons are decidedly weak, they are also the longest lived of the species, with a median age of 300, and some living to be as old as 500 or 600 years old.