He along with many Tiresians were abandoned on Tirol by the Masters as they were deemed useless to them. As a result, the Tirolian homeworld was left defenseless as the Robotech Masters sought Earth in order to retrieve Zor's Protoculture Matrix. As a result, Tirol was conquered by the forces of the Invid Regent and enslaved. However, its inhabitants were freed by the timely arrival of the Pioneer Expedition who arrived aboard the SDF-3. The efforts of the Robotech Expeditionary Force freed Tirol from the Invid but stranded them in Tirolspace.
Learning from the Tiresians of the Masters departure, an expedition was planned by the REF which would be led by Major John Carpenter in order to return to Earth to protect it from their assault. Special envoy ambassador Trell was selected to cement the alliance between the new Tirolian republic and the REF. He was also chosen to accompany Major Carpenter for his knowledge on Masters and Invid. However, their ship was trapped by a power field surrounding the Valivarre system that was generated by Station V-1.
Identifying their attackers as Invid, Trell was taken aboard the Invid space station where he was taken before Commander Voxel alongside Major Carpenter and a fellow Human Captain. Trell along with the Humans remained silent leading to them being tortured by stun rods but were later escorted to prison cells to ensure they survived. Trell later briefed Carpenter in a plan to pretend that they were critically wounded in order to access their ship. The Invid complied in order to ensure the survival of their prisoners. Once aboard, they used the opportunity to escape and free their crew.
Knowing that the Invid station posed a threat, Trell decided to use a hover sleds autopilot in order to travel directly to the controlling Invid Brain. Once there, he neurally linked with the Brain in order to cause it to self-destruct. However, the act critically wounded Trell and he died onboard Carpenter's ship ater it managed to escape. The Humans later conducted a funeral in honor of the Tirolian ambassador and launched his coffin in space in recognition for his bravery.