Kassandra is the canonically chosen protagonist of Assassin’s Creed Odyssey.
Odyssey allows players to select either Kassandra or Alexios as the playable character. Ubisoft’s official narrative materials identify Kassandra as the canon protagonist, while the other sibling appears in the story as Deimos. The player’s choice changes who occupies those roles during an individual playthrough.
Released in 2018, Odyssey is set in ancient Greece during the Peloponnesian War, beginning in 431 BCE. Kassandra is a mercenary descended from King Leonidas of Sparta and becomes involved in conflicts involving Athens, Sparta, the Cult of Kosmos, and the First Civilization.
This canon distinction is easy to miss because both characters can be selected and receive comparable gameplay content. It differs from games with a single fixed hero. Kassandra later appears in downloadable content that connects Odyssey to the wider Assassin’s Creed timeline.