The fictional Parisian Assassin protagonist in Assassin's Creed Unity is Arno Dorian. He is an Austrian-born French Assassin whose story unfolds during the French Revolution.
Arno is adopted by François de la Serre, the Grand Master of the French Templars. After de la Serre is murdered, Arno is blamed for the crime and imprisoned. His imprisonment brings him into contact with Assassin teachings, beginning his path into the Brotherhood and his investigation of the killing.
Arno's close relationship with Élise de la Serre is an important part of the narrative. Élise is a Templar and François de la Serre's biological daughter, so the pair are connected by both affection and opposing organizations. She is not the playable protagonist, a distinction that helps separate her from Arno in character questions.