Clearly, the Xena screenused props are very popular but really hard to find one in good condition and with the COA available. It's a sword that is "one of a kind", I really never see before a retractable Xena metal sword on sale. I've seen screenused resin/foam Xena swords in particular collections of xenites, although are quite difficult to find any of them at all. The COA says that was used in the latest season from the tv show, so I image it is from season 6, also the tone and shape of the guard and pommel remind me season 6 episodes. About the blade, is maybe the most interesting part, in this case, because is retractable. As you know, I've got the centaur metal retractable sword and arent the same. This one can retracts and after the blade is inserted inside the sword when it's leaning on something, it has a "spring" mechanism that allows the blade to return to the initial positition. Very interesting, and I didn't know it till I got it on my hands.
Which episodes was used? Well, that's difficult to know exactly. Although, I've got in my mind two episodes that maybe was used because Xena sticks in the sword, and the camara capture that moment. One, in the episode "Motherhood" from season 5 when Xena killed Athena, there's a close-up screencap that makes me think can be that instant. And two, when Xena stuck the sword to Mephistopheles in the "Haunting of Amphipolis" from season 6.