Duos (デュオス Dyuosu) is a spirit ka in the Yu-Gi-Oh! anime.
"Duos" was Seto's ka, summoned to stop Bandit King Bakura. It has the ability to increase its power by slaying its allies with the Duos blade.
Its relationship to Seto and Graveyard-centric effect make it loosely reminiscent of the card "Swordstalker", which was used by Seto Kaiba.