The Galgano Sword in the Stone inside the Montesiepi Chapel by Adrian Michael. This is the actual sword in stone, now kept under glass and lock and key. The sword has been verified as an authentic 12th century sword. Galgano was beatified four years after his death.
I had a fighter that was "gifted" a rune sword by the DM. It had a curse: if I rolled a 1 the sword would absorb my soul. Course I didn't know that until I rolled a 1. My party saved me, forgot to lose the sword, later fought some monsters, and rolled a 1 again. Our Warpriest sacrificed his life to save me -- I still suffer guilt.