Season 2 Episode 08 - Ten Little Warlords
Xena is still trapped inside Callisto's body and has been invited to a contest held by Ares, but it is addressed to Callisto and Xena knows that Ares knows that she is Xena not Callisto. She decides to go along and see what is going on and soon fined out that Ares's sword has been taken and King Sisyphus is going to give it to the warlord who can beat a fierce monster, that person will then become the knew God of War. As Ares hasn't got his sword he is now mortal, so he can die and get drunk and have a hangover. He soon experiences two of the things mentioned and nearly dies when he is put in a trap set by King Sisyphus when he goes to help Xena.
Xena finds out that King Sisyphus has made a deal with Hades in return he gets the sword of Ares, knowing that all the warriors invited to the contest will kill each other of and there is really no monster that they have to kill. Xena gives Ares his sword back in return for her normal Xena like body.