The Vorlons have an "Empire" that encompasses an undefined volume of space near the territories of the Young Races. How they govern themselves and, in fact, just how many Vorlons exist isn't clear: only two were actually seen in the course of the series. Their representative at Babylon 5 is an Ambassador, but he was able request or order an attack on the other First One race with a major presence in the galaxy, the Shadows.
The Vorlons regard themselves as mentors for the Young Races, having remained in the galaxy -- when most of the other First Ones went "beyond the Rim" -- to guide them toward building thriving, well-organized civilizations. Rivalry with the Shadows, who have a different approach to guiding the development of the Young Races, has caused the Vorlons to become far more aggressive and reactionary in their approach to their goal than originally intended; they have come to view themselves as parental figures to be obeyed, rather than advisors.
Vorlons have an energy-based physiology with only an ephemeral physical presence. In spite of their minimal material characteristics, there are exotic poisons that can seriously harm or kill them. Vorlons are otherwise quite difficult to injure, as most physical objects and energy-weapon bursts will pass through their bodies with little or no effect.telepathic abilities, but their scope is unclear. They appear to be able to establish telepathic contact at interstellar distances, but their telepathic contacts with the Young Races almost invariably occur when the subjects are asleep. Ambassador Kosh once told Captain Sheridan that that was the only time Sheridan's mind was "quiet enough" to hear him. On the other hand, Kosh was able to telepathically alter the perceptions of hundreds or thousands of Young Race observers at once, causing each of them see him as an angelic figure of their own race. In general, Vorlon telepathic abilities seem to be more effective when subjects have been modified or conditioned to be susceptible: all of the Young Races have been conditioned to see Vorlons as angelic beings, and Lyta Alexander (who seems the most vulnerable to Vorlon telepathic abilities, despite her own formidable telepathic powers) has undergone extensive physical and psychic modification by the Vorlons.
Vorlons typically wear an armored life support system called an "encounter suit" when interacting with other races. Vorlons in their suits have demonstrated the ability to remotely apply force, generate electric arcs, emit high-pitched sounds that can crack glass, and surround themselves with force-field bubbles. It is unclear which of these abilities are features of the encounter suit and which are natural abilities of the Vorlons.
Vorlon technology is advanced far beyond that of the Young Races. While based on organic technology, their ships' power and durability is far greater than that of Young Race ships of similar size and comparable to Shadow ships of similar size. If sufficiently motivated, the Vorlons can assemble fleets of thousands of warships. Their fleet includes a few dedicated "planet killers", ships several kilometers in diameter with sufficient firepower to render a planet uninhabitable in a few hours.
While not expansionist, the Vorlons are fiercely protective of their territory and its secrets. Any ship entering their space without invitation is subject to attack.
Vorlons in Debates
The actual firepower and effect of the Vorlon Planet Killer is a frequent subject of debate, as it's never seen in action. Fivers frequently insist that the vessel can blow planets apart like the Death Star, but evidence from the series does not support that claim.