Humans have yet to officially set foot in the Krell System. Located on the opposite side of Xi'An territory, Krell is home to the Kr'thak species, whom the UEE has had no formal interaction with. The Xi'An, however, have had a tempestuous relationship with them for the last seven hundred years, ultimately culminating in a devastating century-long conflict loosely translated as the Spirit Wars.
Advice for travelers seeking to visit Krell (and the Kr'Thak) is few and far between. It is entirely unknown what goods they might be interested in trading, what they produce natively or what they would even consider black market items. It's also unknown exactly how to reach them… or just what reaction the Xi'An star patrols would have to a human traversing their territory for the purpose of doing business with their ancient enemies.