In Assassin's Creed Odyssey, Kephallonia is the birthplace of Kassandra and Alexios.
The game presents Kassandra and Alexios as siblings from the Spartan Agiad royal line, with the player choosing which sibling becomes the protagonist. Their early family story is tied to the island of Kephallonia, where the playable adventure begins after years of exile and hardship.
Kephallonia is also the first region explored in Odyssey. From there, the protagonist travels through a large version of the ancient Greek world, including Attica, the Peloponnese, the Aegean islands, and other regions. The island is therefore both a biographical detail and the starting point of the journey.
Odyssey is set during the Peloponnesian War in the fifth century BCE. It is a fictional adventure built around real Greek places, political powers, and historical figures, rather than a literal record of one individual's life.