Which Assassin's Creed game introduced the Greek warrior Kassandra?

Assassin's Creed Odyssey introduced the Greek warrior Kassandra.

Released in 2018, Odyssey allows the player to choose between Kassandra and her brother Alexios as the playable protagonist. The game's canon novelization identifies Kassandra as the central character, although the game itself supports either selection.

Odyssey is set in Greece during the Peloponnesian War, beginning in 431 BCE. Its world includes mainland regions and islands, and its role-playing systems allow dialogue choices, branching quests, equipment changes, and different outcomes.

Kassandra is a descendant of Leonidas I of Sparta and carries the broken spear associated with her family. She is not a member of the later Assassin Brotherhood in the conventional sense, because the game predates the historical organization shown in several other entries.