In Assassin's Creed Odyssey, you have the option to wear different sets of Armor and the best armor is in AC Odyssey as usual “Legendary”. You can have a total of 15 such legendary armor sets in your inventory. (All available legendary armor sets: Snake Set, Agamemnon Set, Athenian War Hero Set, Achilles Set, Amazons Set, Immortal Set, Pirate Set, Spartan War Hero Set, Greek Heroes Set, Arena Fighter's Set, Artemis Set, Pilgrim's Set, Demigod Set, Pegasus Set and Spartan Renegade Set)
The legendary armor looks very elegant and also they increase your stats and give you extra abilities that can be very useful especially in combat. A legendary set comes with five pieces: head, arms, waist, torso and legs. If you unlock all these pieces, then you will be able to unlock a set bonus in the form of another ability.
To get Legendary Armor set in AC Odyssey you must defeat the cultists. Most of the sets you get when you destroy the individual cultist branches. With a few exceptions, every cultist drops a legendary piece of armor.
Furthermore, there is one set for each of you when you complete a certain quest and prove yourself in arena battles. You will also receive some legendary armor pieces after completing the story and finding certain legendary chests.
Besides, you can also buy legendary sets in the game store with Helix credits.