Xena makes it seem like she has met Ares for the first time in this episode, but it is contradicted in other episodes especially in the Hercules TLJ episode "Armageddon Now Pt. 2" where Ares is right by Xena's side when she was a warlord. Of course, that is an alternate reality, so perhaps the timeline has already been altered. Also, in "Chakram" they reveal that Ares stole the Dark Chakram and gave it to Xena. Perhaps he sent it through an intermediary.