When the Hetzal system was threatened by hyperspace anomalies from the Great Hyperspace Disaster, Tarr was sent over by the ministry to assist Minister Zeffren Ecka. He was able to bring up a map of the anomalies in the star system by combining the feeds from the remaining undestroyed satellites, and later picked up a transmission from Jedi Master Avar Kriss reassuring the people of Hetzal that help was on the way.
After the Emergence in the Hetzal system had ceased, Keven worked onboard the Third Horizon, monitoring the reconstruction of the Legacy Run.
Tarr later took a job with the San Tekka clan. After the Nihil marauders established the Occlusion Zone and claimed ten sectors of the Outer Rim, the Republic reached out to the San Tekkas, who sent Tarr to assist. Tarr led a Republic Defense Coalition research team in attempting to find a way to breach the Stormwall barrier that surrounded the Occlusion Zone.
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- Star Wars: The High Republic Character Encyclopedia