|“Jee, I dunno,” Rainbow muttered. “Not everypony is as curious as you, Doc.”
“I'd rather describe myself as... as...” Theanim tapped his chin in thought, smiled, and said, “'Exploration Friendly.'”
|- Ynanhluutr, "The Things That You Bring Back"|
While performing his regular duties for the Order, his ship (the Midnight Dreary) was wrecked on the Nealend Atoll due to Ultimo's interference. He and several other Continentalists were stranded on the atoll for months until the arrival of Rainbow Dash, Sinrar, and Nick. He assisted Rainbow in taming Ultimo and ended up being carried into the machine world with her, where he took many photographs.
He has always had a scientific skepticism towards Rainbow and her otherworldly mission, but since his experience in the machine world he has had faith in her mission, even though he cannot understand or prove the things she knows.
After leaving Nealend, Theanim takes Rainbow with him towards Rust as a way of repaying her for rescuing everyone. He and his friend Echo then become involved in the plot to dismantle the Syndicate, and demonstrates his faith by selling the Midnight Dreary to fund their plot, on the condition that Rainbow uses his camera to provide concrete evidence of the Syndicate's corruption. He presents this evidence to the congregation at the Marine Auction House of Shoggoth, which incites the anti-corruption investigation that they desired.
After the events in Shoggoth, Theanim reappears before the Council of Verlaxion to testify of the integrity of Rainbow's character and to urge the Council to focus their efforts on stability and reconciliation. He, with the help of Keris, was instrumental in the initiative to migrate the surviving Luminards from Pine Prefecture to a much more suitable home at Sun Roost.
As one Rainbow's most faithful friends on Rohbredden, he is one of the few who still knows the secret truth behind the "murder" of Verlaxion, a truth which he keeps secret despite his own conscience.