Sisyphus was approached by Celesta: Sister of Hades who has come to take him to the Underworld. Sisyphus manages to trap Celesta in chains causing no one in the world to die. Hades approached Xena and Gabrielle and asked them to free Celesta from Sisyphus. Karis helped Xena and Gabrielle free Celesta, but Sisyphus escaped (XWP "Death in Chains").
Sisyphus tricked Timuron into taking his place in Tartarus. Luckily, Hades noticed the deception and asked Hercules to help get the real Sisyphus to the Underworld. Sisyphus wanted Timuron out of the way because the Oracle of Delphi had informed him that Timuron's wife Daphne could bear his child. Sisyphus was desperate for an heir since Karis was barren. Daphne refused Sisyphus' advances. When Hercules came to bring Sisyphus to the Underworld, Sisyphus claimed that he was called early due to a disagreement with Zeus. With help from Karis, Daphne, and Iolaus, Hercules was able to capture him and take him to the Underworld. Hades then had Charon take Sisyphus to Tartarus (HTLJ "Highway to Hades").
Sisyphus later escaped from the Underworld and had stole the Sword of Ares. He holds a contest where whoever slays the Barrachus will win the Sword of Ares. When Xena and Ares win the contest, Sisyphus then pleads with Xena to destroy Ares and claim the prize, but Gabrielle and Joxer burst in and reveal the secret behind The Barracus. Bitterly defeated, Sisyphus confesses that Hades promised to make him the new God of War if he delivered the world's ten best warriors to him. Xena hands the sword back over to Ares then watches solemnly as Sisyphus returns to his previous punishment (XWP "Ten Little Warlords").
In Greek mythology Sisyphus or Sisyphos (/ˈsɪsɪfəs/; Ancient Greek: Σίσυφος Sísuphos) was the king of Ephyra (now known as Corinth). He was punished for his self-aggrandizing craftiness and deceitfulness by being forced to roll an immense boulder up a hill only for it to roll down every time it neared the top, repeating this action for eternity. Through the classical influence on modern culture, tasks that are both laborious and futile are therefore described as Sisyphean.