Okaara is the thirteenth planet in the Vega system. Ages ago, the Guardians of the Universe made a pact with the Keeper of the Orange Light. On the emotional spectrum, the Orange Light represented avarice and was of great threat to the Guardians' plans. In exchange for keeping the orange light buried and out of reach, the Guardians agreed to leave Okaara and the entire Vega system outside of their established jurisdiction. Also the Guardians would get back a vessel that contained Parallax, that had been stolen from them.
Okaara is also where Princess Koriand'r and Komand'r of Tamaran were taken to train in deadly combat techniques with the venerated Warlords of Okaara as a part of a coming of age ritual, due to Blackfire's attempted murder of Starfire during sparring the Warlords had to separate them and have them return at a later date to finish. Starfire only completed the ritual on the promptings of Raven, who's pure spirit resided within her, in order to buy time while Raven's evil self was running loose at the time.
Also, as another part of their duties, the Warlords keep a sacred vigil over the Vegan systems goddess X'Hal, they being alone with the ability to keep the goddess more or less sane, preventing her from going on another destructive rampage that once claimed three planets. During their visit to the planet, the New Teen Titans and the Omega Men remarked how the subterranean world of Okaara was somehow brightly lit below the surface, and that in the chamber where X'Hal was kept felt almost holy, something that intensified when X'Hal chose to manifest before them.