What is the name of the ancient Greek artifact central to Assassin's Creed Odyssey?

The ancient Greek artifact central to Assassin's Creed Odyssey is the Spear of Leonidas.

The spear is a broken Isu weapon inherited by the game's protagonist and used as a powerful combat tool. Its connection to Leonidas of Sparta ties the playable character's family history to the opening battle at Thermopylae.

Although called a spear, the object is not treated as an ordinary military weapon. Its Isu origins give it extraordinary abilities, and it is upgraded throughout the adventure as the player investigates its history and powers.

Odyssey also includes other important artifacts, including the Staff of Hermes Trismegistus. That staff is significant to the game's later story, but it is not the artifact identified with Leonidas and the protagonist's inherited weapon.