Hardesty was an agent for the American Central Intelligence Agency, probably a colleague of Joe Wexler, before joining the Tyrants.
Scott Hardesty has been a member of the Tyrants for years, and he is skeptical of any new recruits the Tyrants plan to hire. Him and Ben Saxon argue while they work together, as Saxon has a conscience that keeps him from massacring unarmed civilians, which makes him a liability to the group. He fights Ben Saxon in the Tyrant Jetliner as he tries to escape, although Saxon manages to get away by spraying a fire extinguisher at him.
Later in Icarus Effect, he is posted at a library near the Palais des Nations, as a fail-safe to kill Bill Taggart, leader of Humanity Front, in case Ben Saxon does not shoot him himself. At the last second, Ben saves Taggart, then fights Hardesty in the library. He finally kills Hardesty by stabbing him through the skull with his own arm blade.