I found a Firey Greatsword in my inventory, after _months_ of not playing.

I know for sure I don't have one. Heck, I'm not entirely sure I even made the Iron Broadsword or Silver Broadsword.

This is my singleplayer only, all-legit character.

I'm about to go check if I've loaded the wrong one, but if I have, I have no idea how I got it. Even if I _did_ load the wrong one, I've never had a Firey Greatsword.