Jussac operates as a secondary antagonist, serving as a steadfastly loyal subordinate to Captain Rochefort within Cardinal Richelieu's guards. He consistently appears at Rochefort's side, functioning directly as his right-hand man in operations designed to obstruct or capture D'Artagnan and the musketeers.

His character is defined by his unwavering loyalty to Rochefort and his position within the Cardinal's faction. He actively pursues the protagonists alongside Rochefort, such as chasing D'Artagnan and Aramis following an arson attempt. During these pursuits, he shares comedic moments with Rochefort, like their chase being thwarted by a flock of sheep blocking their path, which leads to Rochefort losing his temper while Jussac is present.

No background details appear regarding Jussac's origins or personal history. His character does not undergo significant development or possess a distinct personal arc across the series or films. He remains a consistent presence within Rochefort's operations throughout the narrative.

Similarly, no concrete details are provided about his personal traits, motivations beyond serving Rochefort and the Cardinal, or relationships outside his professional association with Rochefort. His presence reinforces Rochefort's authority and provides opposition within specific plot sequences involving the Cardinal's guards.