In 2269 he stole his race's holy artifact, the Soul of the Skorr, hoping that this would ignite a galaxy-wide jihad and reestablish the Skorr as a warrior race. Insane, Tchar could not cope with a peaceful galaxy and planned to lead his people in this war.
When the Vedala sent teams to recover the artifact from an unstable "mad planet" , Tchar joined Kirk, Spock, Sord, Em/3/Green, and Lara, planning to sabotage the quest. As the team neared the strange building housing the missing artifact, Tchar was "abducted" by creatures evidently native to the mad planet.
When the team gained entry to the building, he reappeared and challenged the remaining members of the party to honorable combat. He could not allow them to live, but was impressed by their skill in reaching the artifact. He disabled the internal gravity so that his ability to fly would not give him undue advantage. Kirk and Spock, experts in zero-gravity combat , were able to defeat him.