Gosta is a reed-thin man with a complexion the color of old parchment, suggesting years spent away from the Phandalin sun. His most striking feature is a pair of pale, silver-grey eyes that seem to dart with an independent intelligence behind thick, round-rimmed spectacles. He moves with a frantic, bird-like energy, his hands constantly fluttering to adjust his glasses or smooth his ink-stained apron. Unexpectedly, he possesses a pair of heavy, military-grade leather boots that are kept polished to a mirror shine, a stark contrast to his otherwise dusty and neglected attire. When he is nervous, which is often, he smells faintly of ozone and dried lavender.

Gosta is a man trapped between paralyzing anxiety and a rigid, moralistic core. He is obsessively meticulous with his ledgers, finding safety in the predictability of numbers that the chaotic town of Phandalin lacks. While he is stuttering and submissive when face-to-face with the Redbrand ruffians, he is secretly biting and cynical in his private notes, venting his frustrations onto the page. He is exceptionally generous to the local orphans, often 'losing' small pieces of copper in their vicinity, but he is notoriously suspicious of well-armed adventurers, viewing them as nothing more than catalyst for more trouble.

Formerly a mid-level auditor for the Lord's Alliance in Neverwinter, Gosta fled the city after a corruption scandal that he uncovered led to the 'accidental' death of his superior. He sought anonymity in the frontier town of Phandalin, taking a job under Halia Thornton at the Miner's Exchange. For two years he enjoyed the quiet, until the Redbrands arrived. Since then, he has lived in a state of quiet terror, forced to facilitate their 'protection' money exchanges and supply requests while keeping a secret, detailed tally of their every purchase in the back of his mind.