Location: Black Friday Shop - Game Menu
Price: 3,000 Gold
Sellback: 750 Gold
Rarity: Rare Rarity
Description: At the proper angle, aiming it right can slice and dice one's own shadow temporally. It's not necessary, but it demonstrates how sharp the katana is.
Note: Also see Blademaster Assassin Masked Locks.
Thanks to SirJonstar.