Legacy of the First Blade

The Legacy of the First Blade is an upcoming downloadable content expansion package for Assassin's Creed: Odyssey, set to be released in December 2018. It is the first out of two expansion packs for the game, alongside The Fate of Atlantis.

The expansion introduces players to the first person to ever use the Hidden Blade and will reveal more about the history that led to the formation of the Assassins.

Reference

 * Assassin's Creed Odyssey Post-Launch-Details Revealed