Which Assassin's Creed game introduced the playable character Arno Dorian?

Assassin's Creed Unity introduced the playable character Arno Dorian.

Arno Victor Dorian is a French Assassin whose story unfolds during the French Revolution. After the death of his adoptive father, Arno is drawn into the Assassin Brotherhood and investigates a conspiracy involving powerful Templars. His personal relationships and the political upheaval in Paris form the game's central narrative.

Unity was released in 2014 and is set primarily in Paris from 1789 onward. Its version of the city emphasizes dense crowds, detailed interiors and large landmarks such as Notre-Dame. The game also added cooperative missions for up to four players, allowing players to control Arno alongside other Assassin characters.

Arno is sometimes confused with Élise de la Serre, his childhood friend and a playable character in selected cooperative content, but Arno is the main protagonist. Unity is also distinct from Assassin's Creed Syndicate, whose twin protagonists are Jacob and Evie Frye and whose setting is Victorian London.