My plan is so flawless that not even your bungling can interfere this time.
Briardien is a male wildwood elezen with silvery hair. He wears a linen bliaud with white gloves and brown gaskins. He is distinguished by glasses, which often sparkle during a close-up.
In contrast to Hildibrand's buffoonery, Briardien maintains a serious, suave, and professional tone - no matter what situation the former gets him into. He can be also quite arrogant and insufferable at times, and is sometimes overconfident about his plans. Though this is not without cause - again unlike Hildibrand, Briardien is actually quite skilled at his job, with his intuition and ability at piecing together the situation from evidence rarely steering him wrong (and wrong steering usually being the fault of one particular individual).
Briardien introduces himself to Durilda, offering his services in investigating the duelist's threat to steal the Treaty Blade. He later shows up, and much to his annoyance, explains his plan to Hildibrand to catch the thief: distribute several counterfeit Treaty Blades as decoys to lure out the duelist in Coerthas. He reluctantly agrees to let Hildibrand, Nashu, and "Greg" watch the road outside the Observatorium. As Hildibrand and "Greg" argue over who claimed the Bradamante, Briardien concludes the latter's words about winning in duels is a confession. He asks the player and allies to deal with the man in red on the big bridge at Griffin Crossing.
With the culprit seemingly dealt, Briardien confidently hands the Treaty Blade to Durilda who departs with it. Suddenly, the real Durilda walks up stating she was waiting on the docks. Looking over, Briardien finds a discarded mask and realizes they've been had. Suddenly a calling card is flung through Vesper Bay, narrowly avoiding the others and lands squarely in Briardien's forehead. The card reveals the thief plans to steal the "lapis maiden's virtue."
Briardien returns in the third episode, "A Case of Indecency," added in Patch 2.3. He arrives in Costa del Sol offering to help catch the phantom thief at the wedding of Lady Arabelle, based on the previous taunt. As he reviews all the key attendants that may be the thief in disguise, Briardien suddenly notices that Hildibrand was already attending and fraternizing with the Brass Blades, to extreme annoyance. During their investigation, an unfortunate incident on the beach involving Nashu's bombs and (poor) transcripts of the investigation results in an explosion that Briardien misinterprets as an attempt on his life by the phantom thief.
Later, they learn that the thief tried to attack Arabelle's attendant Lewenhart, and was wounded in the hand (and thus would be wearing gloves). As wedding goes underway, Briardien tasked Hildibrand with delaying the bride's arrival while he searches for the gloved interloper. What he did not anticipate was Hildibrand appearing at the wedding, while (very poorly) disguised as the bride. He accused the groom, Vannes, of being the disguised thief based on some dubious logic and was soon chased off by the Brass Blades. However, as the cross-dressed Hildibrand fled, "Vannes" suddenly grabbed the disguised Arabelle, at which point Briardien noticed he was wearing a glove on his right hand. Before he could react, the Man of a Thousand Faces was able to steal her necklace and changes his form to that of a white-clad bandit who escaped. Later, they learn that the necklace was a treasure called "Azeyma's Virtue," prompting Briardien to dryly note they must take care to read between the lines on the phantom thief's next challenge.
Briardien reappears in the 3.15 Scholasticate side story quest, reuniting with the adventurer.