That's true, I did! It was my third or fourth playthrough of the game and had become addicted to Twin Charm (for instance getting advanced weapons your first go round in 65 Million BC). I was fighting Yakra XXXIII (or whatever his number was) when I "got" the weapon. I was incredibly excited because this was a weapon I had never even seen before! I was curious about the strange symbols, and wondered if they somehow represented the untold power of this rare blade. After the battle (and cutscene) I opened my menu and couldn't find it... I thought it was incredibly weird. I saved my game and reset it from a pre-battle save, and tried again. This time it was a no-go. A quick search on then-AOL 3.0 or 4.0 allowed me to recognize that this was a fluke and a glitch.
Alas!