Vallien was a 24th century Vulcan Starfleet officer. He hailed from a polar region of the planet Vulcan, inhabited by a blond-haired ethnic sub-group (a notably different physical feature compared to Vulcan's dark-haired majority). (Star Trek: Arcadia)
Vallien was a student of Sirenahr, a school of thought arising from a different interpretation of Surak's teachings, which sought an emotional "balance", unlike Kolinahr, the purging of all emotions espoused by many Vulcans as the height of virtue in their culture. As a result of his Sirenahr beliefs, he seemed emotionally "warm" and sociable. While occasionally seeming to convey emotions, he never actually felt them. By contrast, he rarely raised an eyebrow as other Vulcans were known to do, in response to external stimuli. He was learned in the practice of mind melds, though claimed not to be a master, and would only engage in the act under extreme circumstances.
Vallien joined the UFS Arcadia's Tactical Department in late 2378. He often manned the bridge tactical station. His exact age was unrevealed, but he was considered young for a Vulcan. He continued serving in this capacity until as late as 2386.
- On Star Trek: Arcadia, images of real-life actors simulated characters. In this sense actor Orlando Bloom represented Vallien (resembling Legolas from Lord of the Rings, who inspired the character).