The Papyrus Blade

Description
At first glance, this sword appears impossible, the blade a paper-thin sheet of metal that looks like it would bend and break at the slightest contact.

Instead, the sword is incredibly formidable against armored opponents, being able to slide into the gaps and crevices in armor with the greatest of ease.

The only disadvantage to the thinness of the blade is that it becomes more difficult to sheath, meaning that those who do not pay attention will find themselves with a thin, deadly cut on the inside of their thighs.

Source
The  can be found in Legendary Chests.

Repair
This item can be repaired with a.